Glossary

362 pages

• 0.8mm thickness0.8mm thickness This is an ideal wall thickness to print on consumer 3D printer since to normally creates sufficient strength and prints in one two passes Details It is common for people to leave their 3D printer unattended printing for…
• 200 mesh200 mesh 200 mesh (a sieve with 200 wires/inch) is the particle size that most minerals used in the ceramic industry are processed to. Details In ceramics , this refers to the particle size of a powder. A 200 screen has 200 wires per inch.…
• 325 mesh325 mesh 325 mesh (a sieve with 325 wires/inch) is the finest particle size that most ceramic minerals can be practically processed to (premium grades). Details In ceramics , this refers to the particle size of a powder. A 325 screen has…
• 3D Design3D Design 3D Design software is used to create dimensionally accurate objects by sketching 2D geometry and transforming it using tools to rotate, extrude, sweep, etc. The software generates the polygon surface. Details It is important to…
• 3D Modeling3D Modeling 3D surface modelling tools enable the creation of objects by starting with a basic shape having polygon surfaces and then subdividing, pushing and pulling the quadrilateral or triangle polygon meshes to form shapes. Details 3D…
• 3D Printer3D Printer Standard 3D printers (not clay 3D printers) are incredibly useful in ceramic production and design, bringing difficult processes within reach of potters and hobbyists. Details This page is about using FDM 3D printers and PLA…
• 3D Printing Clay3D Printing Clay Clay for 3D printing. People are getting carried away with the technology and forgetting the common sense things relating to the clay. Details 3D printers that can extrude a clay paste are available now. These are known as…
• 3D Slicer3D Slicer A slicer is software that can cut a 3MF, OBJ or STL 3D model file into hundreds or even thousands of layers and then control a printer to print them layer-by-layer. Details Slicing software converts an 3D STL , OBJ or 3MF file…
• 3D-Printing3D-Printing Standard 3D printing technology (not printing with clay itself) is very useful to potters and ceramic industry in making objects that assist and enable production. Details When this site refers to 3DP or 3D printing , we are…
• 42 mesh42 mesh This is a bit of a magic number when it comes to particle size reduction of ceramic minerals and clays. 42 mesh represents the practical minimum particle size limit that an industrial hammer mill (coupled with a vibrating screen…
• A.I. in CeramicsA.I. in Ceramics Unbelievable things are happening. Good and bad. A.I. Is polarizing and revolutionizing ceramics. For us at Digitalfire, perhaps the biggest benefit is more enablement of DIY. Details This is huge. And it exploded into the…
• Abrasion CeramicsAbrasion Ceramics Man-made ceramic surfaces are among the most abrasion resistant materials known. Products made to abrade others are also made from bonded ceramic grains. Details Abrasion ceramics can refer to two things: Products that…
• Acidic OxidesAcidic Oxides In glaze chemistry, oxides are classified in various ways to model their contribution to the fired glaze properties Details In glaze chemistry oxides are sometimes classified as basic (RO, R2O group) or acidic (RO2). The…
• AgglomerationAgglomeration The fine mineral, oxide and clay particles used in ceramics often aglommerate during storage or even in the latter stages of production. These must be broken down later. Details In powders and slurries, particles can…
• AI atAI at Digitalfire Organizations are increasingly adopting guidelines ensuring the ethical, secure, and responsible use of artificial intelligence within their organizations. Their policies also include data privacy, bias mitigation, human…
• AlkaliAlkali Alkalies are the strong base fluxing oxides of Na 2 O , K 2 O and Li 2 O . Feldspars are by far the most common alkali sourcing materials, thus the term 'alkali feldspars'. However, frits are also an excellent source and sometimes…
• Alkaline EarthsAlkaline Earths Refers to a group of ceramic fluxing oxides that contribute similar properties to fired glazes. They contrast with the alkalis which are stronger fluxes. Details Glaze chemistry models fired glazes as constructed of oxides…
• All-in-one case moldAll-in-one case mold A method of 3D printing the case mold shell of an entire assembled plaster mold for using in ceramic production. Details The advent of 3D printing is making it possible to print a completely assembled case mold (with…
• AmorphousAmorphous Without a regular structure. Amorphous minerals do not have a repeating crystalline matrix. Glass, for example, is amorphous because it is cooled in the kiln quickly enough that no crystals have an opportunity to form. Related…
• Apparent porosityApparent porosity The relation between the volume of a mass and the volume or water absorbed when the mass is immersed. Got a Question? https://digitalfire.com
• ArtwareArtware Artware, to potters and hobbyists, is pottery made from white-burning clays fired at low temperatures with brightly coloured glazes and decorated using decals, underglazes, lustres, etc. Details News Fall 2021: The hobby casting…
• Ball millingBall milling A method of grinding particles in ceramic powders and slurries. A porcelain, metal or rubber vessel filled with pebbles tumbles and particles are ground between colliding pebbles. Details A device used to reduce the particle…
• Bamboo GlazeBamboo Glaze A high temperature reduction glaze made by adding a small amount of iron oxide to a magnesia matte base glaze Details Usually describes a bamboo colored matte glaze (especially in reduction stoneware ). These are normally…
• Base GlazeBase Glaze Understand your a glaze and learn how to adjust and improve it. Build others from that. We have bases for low, medium and high fire. Details A base glaze is one having no opacifiers , variegators or colorants . Thus it should be…
• Base-Coat Dipping GlazeBase-Coat Dipping Glaze These are ceramic glazes intended for dipping but which contain a gum to enable them to adhere to the body better and tolerate over-layers without danger of flaking or cracking. Details In ceramics and pottery,…
• Basic OxidesBasic Oxides See Acidic. Got a Question? https://digitalfire.com
• Batch RecipeBatch Recipe In ceramics, glazes are made by weighing out dry ceramic powdered materials to fill a recipe. Batch recipes often are a combination of a base recipe and additions. Details The term 'batch' refers to the actual mixture of…
• BisqueBisque Potters and some manufacturers fire ceramic ware twice, once to prepare it for glazing (call bisquit firing) and the second time to melt the glaze onto it. Details Generally, bisque firing refers to the practice of prefiring ware…
• Bit ImageBit Image From ceramic production to pottery we need to take photos, knowing something about the file formats and working with them saves money, time, the environment. Details Digital photographs are "bit images". Ceramic artists and…
• Black CoreBlack Core A common fault in reduction gas fired ceramic ware made from iron bearing clays. The interior cross section of the clay turns black. Details The principal home of information on this issue is in the troubleshooting section in…
• Bleeding of colorsBleeding of colors In ceramics, the edges of overglaze and underglaze color decoration often bleeds into the over or under glaze. How can this be avoided. Details The principal home of information on this issue is in the troubleshooting…
• Blender MixingBlender Mixing An ordinary kitchen blender does a better job of mixing a ceramic slurry than any industrial machine. It even reduces clay particle size and hyper ages it. Details Anyone who has an inexpensive kitchen blender can mix glaze…
• BlungingBlunging In ceramics, the production of glazes and casting slips requires dispersing powders into water to create slurries. A good mixer is essential. Details In ceramics , the mechanical mixing of a slurry is done with a blunger (usually…
• Body BloatingBody Bloating When clay materials and bodies bubble as they melt or over fire. This normally happens in raw materials that contain particulates that produce gases during firing. Details Bloating is a fault that can occur in the firing of…
• Body glaze InterfaceBody glaze Interface In ceramics, the zone of adherence between glaze to the underlying body is called the clay-glaze interface. The integrity of this interface is important to strength and functionality. Details In ceramics , the zone of…
• Body WarpingBody Warping Warping happens during the firing of ceramic ware when there is a high degree of vitrification and inadequate measures are taken during forming and firing to prevent it. Unexpected warping often happens with unstable shapes…
• Bone ChinaBone China A ceramic whose priorities are translucency, whiteness, fired strength and resistance to thermal shock failure. Details Although this mug is made using regular pottery porcelain having some translucency , it cannot compare to…
• BorateBorate Borate glazes, those fluxed with the oxide B2O3, are the most common type used in ceramic industry and hobby for low and medium temperatures. Details The term 'boron' refers to the oxide B 2 O 3 . 'Borate materials' thus contain B 2…
• Boron BlueBoron Blue Boron blue is a glaze fault involving the crystallization of calcium borate. It can be solved using glaze chemistry. Details Boron blue is the bluish haze or clouding in a transparent boron glaze that results from the…
• Boron FritBoron Frit Most ceramic glazes contain B2O3 as the main melter. This oxide is supplied by great variety of frits, thousands of which are available around the world. Details This term is very generic, referring of course to frits that…
• BorosilicateBorosilicate A silicate is an SiO 2 -centric solid ( crystalline or glass). A borosilicate simply is a silicate with boron . In ceramics , the term 'borosilicate' is synonymous with medium and low fire glazes. Boron is seldom employed at…
• Breaking GlazeBreaking Glaze A decorative effect in ceramic glazes that exploits changes in color and character in certain glazes when their thickness varies. Details A decorative effect in ceramic glazes that exploits changes in color and character in…
• Brick MakingBrick Making Brick-making is surprisingly demanding. Materials blending and processing, forming, drying and firing heavy and thick objects as fast as possible are like no other ceramic manufacturing challenge. Details In many places, brick…
• Brushing GlazeBrushing Glaze Hobbyists and increasing numbers of potters use commercial paint-on glazes. It's convenient, there are lots of visual effects. There are also issues compared to dipping glazes. You can also make your own. Details The ceramic…
• Calcia MatteCalcia Matte Calcia matte ceramic glazes are “crystal mattes” while magnesia mattes are “microstructure mattes”. They have a smoother surface but can also have finely textured, even frosty, feathery or sugary surfaces, depending cooling…
• CalcinationCalcination Calcining is simply firing a ceramic material to create a powder of new physical properties. Often it is done to kill the plasticity or burn away the hydrates, carbonates, sulfates of a clay or refractory material. Details The…
• Calculated Thermal ExpansionCalculated Thermal Expansion The thermal expansion of a glaze can be predicted (relatively) and adjusted using simple glaze chemistry. Body expansion cannot be calculated. Details Digitalfire Insight-live calculates the coefficient of…
• CandlingCandling Refers to the practice of slow-heating a kiln during early stages to give mechanically-bound water a chance to escape. Details The practice of slow-firing ware through the critical temperature surrounding the boiling point of…
• Carbon BurnoutCarbon Burnout Ceramic materials, especially clays, often contain carbon and organic compounds. When they are fired in a kiln, these must burn out, often producing complications. Details Ceramic bodies and glazes contain materials that…
• Carbon trap glazesCarbon trap glazes A type of ceramc glaze. Details Glazes with variegated patterns of grey and black from carbon trapped below the surface. The effect is created by fuel firing without adequate oxygen in early stages to build up soot…
• CAS NumbersCAS Numbers CAS (Chemical Abstracts Service) is a registry of chemical identification numbers maintained by the American Chemical Society. Although ceramic materials are generally minerals or processed minerals rather than chemicals, most…
• Casting SlipCasting Slip Casting slips are among the easiest clay bodies to make yourself. The ability to make and tune your own will open many doors in your production process. Details Anyone can make casting slip . Materials needed are available at…
• Casting-JiggeringCasting-Jiggering A process in ceramic production where items are slip-cast first and then finished using a jigger wheel. Details The slip-casting process is well adapted for producing non-functional ware, especially having thinner walls.…
• Catch GlazeCatch Glaze A catch glaze of the lower section of a piece of ceramic or pottery is often needed to arrest the flow of reactive runny glazes (so they do not run down on to the kiln shelf). Details A glaze used on lower sections of ceramic…
• Celadon GlazeCeladon Glaze A type of stoneware glaze normally fired in a high temperature reduction atmosphere kiln. It is transparent and stained green or blue by the presence of iron oxide. Details A green or blue-green reduction fired glaze that has…
• CeramicCeramic Ceramic materials are among the hardest and most heat resistant materials known. Ceramics spans the spectrum from ancient terra cotta to modern hi-tech materials. Details A solid produced by the fusion of non-metallic mineral or…
• Ceramic BinderCeramic Binder Binders are glues that harden ceramic powders as they dry. They enable improved surface adherence. And slower drying. Details A classic ceramic glaze (a water based slurry of feldspar , clay and silica powders) can can be…
• Ceramic DecalsCeramic Decals This process of printing a design (using ceramic inks) onto film-coated paper to create a waterslide transfer. On wetting, the film decal can slide off the backing on to the glazed ware. Details A method of printing designs…
• Ceramic GlazeCeramic Glaze Ceramic glazes are glasses that have been adjusted to work on and with the clay body they are applied to. Details A glaze is a glass made of powdered minerals and man made materials whose recipe has been tuned to melt to the…
• Ceramic Glaze DefectsCeramic Glaze Defects Ceramic glaze defects include things like pinholes, blisters, crazing, shivering, leaching, crawling, cutlery marking, clouding and color problems. Details Ceramic glaze defects include things like pinholes , blisters…
• Ceramic InkCeramic Ink You can make your own ink (or buy it) and apply it to ware using various methods (e.g. rubber stamping, silk screen, inkjet decals). Details Ceramic inks are simply carriers of ceramic fine particled metallic oxide pigments…
• Ceramic MaterialCeramic Material Ceramic materials are employed in the ceramic industry to make glazes, bodies, engobes and refractories. We study them at the mineral, chemical and physical levels. Details Ceramic materials are employed in the ceramic…
• Ceramic OxideCeramic Oxide In glaze chemistry, the oxide is the basic unit of formulas and analyses. Knowledge of what materials supply an oxide and of how it affects the fired glass or glaze is a key to control. Details An oxide is a combination of…
• Ceramic SlipCeramic Slip The term Slip can have various meanings in traditional ceramics. Details In ceramics , this term can refer to a number of things: -A clay slurry poured into molds to be cast into shapes. The slip is deflocculated to minimize…
• Ceramic StainCeramic Stain Ceramic stains are manufactured powders. They are used as an alternative to employing metal oxide powders and have many advantages. Details Stains are man-made colorant powders used in glazes, bodies and engobes . They are…
• Ceramic TileCeramic Tile Tile manufacture is the largest sector of ceramic industry. Engineers overcome the very difficult technical challenges of drying and firing defect-free, flat and durable tile. Potters can do it too. Details If you wish to make…
• Ceramic TransferCeramic Transfer A method for applying designs underglaze . Water-based colorants are silk-screened onto rice or tissue paper, dried, then the paper is applied, color-side-down, to a leather hard clay surface. Using a damp sponge and rib…
• CeramicsCeramics This term generally refers to the industry that produces the non-metallic objects we use every day (like porcelain, tile, glass, stoneware). Details The word ceramics can be used in multiple contexts, but here we think of it as…
• CharacterizationCharacterization In ceramics, this normally refers to the process of doing physical or chemical testing on a raw material to accurately describe it in terms of similar ones. Details Characterizing a clay by making observations, doing…
• Chemical AnalysisChemical Analysis In ceramics, raw material chemistry is expressed a chemical analyses. This is in contrast to fired glaze chemistries which are expressed as oxide formulas. Details Conceptually we consider ceramic fired glazes as being…
• ChromaticityChromaticity A method for evaluating color in the ceramic tile industry. Related Information Links URLs http://en.wikipedia.org/wiki/Chromaticity Chromaticity at Wikipedia Got a Question? https://digitalfire.com
• ClayClay What is clay? How is it different than dirt? For ceramics, the answer lies on the microscopic level with the particle shape, size and how the surfaces interact with water. Details The term 'clay' is used in different ways. Potters…
• Clay bodyClay body A term used by potters and in the ceramic industry. It refers to the earthenware, stoneware or porcelain that forms the piece (as opposed to the engobe and covering glaze). Details For potters and in industry, the term "clay" is…
• Clay Body PorosityClay Body Porosity In ceramics, porosity is considered an indication of density, and therefore strength and durability. Porosity is measured by the weight increase when boiled in water. Details In ceramic testing this term generally refers…
• Clay StiffnessClay Stiffness In ceramics, clays exhibit plasticity in accordance with their recipe but also the water content. Each types of forming method has an ideal combination of stiffness and plasticity. Details Clay bodies used in machine forming…
• Clays for ConstructionClays for Construction No material goes farther back in construction history than clay. In recent years exciting new techniques and technologies centering on this age-old material are changing parts of the building industry. Overview of…
• Clays for Ovens and HeatersClays for Ovens and Heaters Thermal mass heating ovens (such as Rocket Mass ovens or heaters, Cob ovens, pizza or baking ovens) employ heat sinking mechanisms to store energy. Their construction often involves the use of heavy blocks…
• Co-efficient of Thermal ExpansionCo-efficient of Thermal Expansion The co-efficient of thermal expansion of ceramic bodies and glazes determines how well they fit each other and their ability to survive sudden heating and cooling without cracking. Details Co-efficient of…
• Code NumberingCode Numbering In a ceramics lab, studio or classroom specimens of hundreds of glazes and bodies may be present. A code numbering system that links these to written or computer records is essential. Details In the context of this site the…
• Coil potteryCoil pottery Making pottery by laying down layers of coils and working them together into an even wall. Got a Question? https://digitalfire.com
• ColloidColloid In ceramics some clays of are of such exceedingly small particle sizes that they can stay in suspension in water indefinitely. But unlike common colloids, clays have a secret weapon. Details Colloidal particles are so small and…
• ColorantColorant In ceramics and pottery, colorants are added to glazes as metal oxides, metal-oxide-containing raw materials or as manufactured stains. Details Although colorants are added to bodies, most people think of them as materials that…
• Commercial hobby brushing glazesCommercial hobby brushing glazes These are an incredible benefit to pottery beginners and pure hobbyists. But they can also be an obstacle to progress and affordability as your skills improve. Details This page discusses commercial glazes…
• Cone 1Cone 1 The Cone 1 range is commonly employed in industry for durable products (e.g. structural). To a potter it does not sound possible that stoneware-strength could be achieved at cone 1, but the secret is terra cotta clays. While not…
• Cone 5Cone 5 Also called "middle temperature" by potters, cone 5 (~2160F/1180C) refers to the low end of the temperature range at which most hobby and pottery stonewares and porcelains are fired. Details Many potters are moving from cone 6 (…
• Cone 6Cone 6 Also called "middle temperature" by potters, cone 6 (~2200F/1200C) refers to the temperature at which most hobby and pottery stonewares and porcelains are fired. Details This refers to the medium temperature oxidation range (or…
• Cone plaqueCone plaque Cones have been a traditional way of measuring the temperature ceramic kilns for many decades. Plaques are the setters that hold the cones at the right angle. Details A stand or rest for holding cones during firing. Plaques are…
• Content Management SystemContent Management System A content management system ( CMS ) is a software application that enables users to create, manage, and publish digital content on websites without needing to write code from scratch. A CMS generally has two main…
• Copper RedCopper Red The color red is very difficult to achieve in ceramics. The most vibrant red within the reach of the average potter is the color produced by copper in reduction firing. Details The color red is very difficult to achieve in…
• Cordierite CeramicsCordierite Ceramics Cordierite is a man-made refractory low thermal expansion crystalline solid that forms at very high temperatures (in the right mix of kaolin and talc). Details Cordierite ceramics are well known for their low thermal…
• Crackle glazeCrackle glaze Crackle glazes have a crack pattern that is a product of thermal expansion mismatch between body and glaze. They are not suitable on functional ware. Details A type of ceramic glaze that is intentionally crazed . Crazing is a…
• CristobaliteCristobalite In ceramics, cristobalite is a crystalline form of silica formed in the matrix of clay bodies as they fire in the kiln. Silica can also exist as quartz (the most common) and tridymite. Details Cristobalite is a crystalline…
• Cristobalite InversionCristobalite Inversion In ceramics, cristobalite is a form (polymorph) of silica. During firing quartz particles in porcelain can convert to cristobalite. This has implications on the thermal expansion of the fired matrix. Details…
• CRMCRM Customer Relationship Management ( CRM ) is a strategy, process, and often a software solution used by businesses to manage their interactions and relationships with current and potential customers. It centralizes customer…
• CrucibleCrucible In ceramics, potters make crucibles to melt frits, stains and other materials. Crucibles are made from refractory materials that are stable against the material being melted in them. Details Crucibles are most commonly used in…
• Crystalline glazesCrystalline glazes A type of ceramic glaze made by potters. Giant multicolored crystals grown on a super gloss low alumina glaze by controlling multiple holds and soaks during cooling Details Crystals can form during cooling and…
• CrystallizationCrystallization Ceramic glazes form crystals on cooling if the chemistry is right and the rate of cool is slow enough to permit molecular movement to the preferred orientation. Details Depending on the chemistry of a glaze melt, it may…
• Cuerda SecaCuerda Seca A method of decorating terra cotta clay tiles by flood-filling liquid glaze into areas delineated by colored wax or grease lines. Details Using this technique, a heavy-line drawing of ceramic-stained wax or grease is…
• Cutlery MarkingCutlery Marking Ceramic glazes that mark from cutlery are either not properly melted (lack flux), melted too much (lacking SiO2 and Al2O3), or have a micro-abrasive surface that abrades metal from cutlery. Details In glazes with this…
• DecompositionDecomposition In ceramic manufacture, knowing about the how and when materials decompose during firing is important in production troubleshooting and optimization Details Ceramic kilns are molecule-breaking machines. Mineral powders in a…
• DeflocculationDeflocculation Deflocculation is the magic behind the ceramic casting process, it enables slurries having impossibly low water contents and ware having amazingly low drying shrinkage Details In ceramics , when we speak of deflocculation ,…
• DehydrationDehydration Dehydration in clay refers to the process of the evaporation of water during air drying (physical) and the removal of chemically bound water during firing (chemical). As air drying proceeds, water between the clay particles…
• Differential thermal analysisDifferential thermal analysis A test done on clays to deduce their mineralogy . Related Information Links URLs https://en.wikipedia.org/wiki/Differential_thermal_analysis Differential thermal analysis DTA testing at Wikipedia URLs…
• Digitalfire APIDigitalfire API Insight-live .com cloud servers hold a lot of subscriber data, almost all of it confidential. Traditionally our webapp reads and writes directly to the database through functions designed to abstract it. In recent years…
• Digitalfire ForesightDigitalfire Foresight Database software for DOS made by Digitalfire from 1988 until 2005 and was used to by ceramic technicians to catalog recipes, materials, test results and pictures. Details Database software for DOS made by Tony Hansen…
• Digitalfire InsightDigitalfire Insight A downloadable program for Windows, Mac, Linux for doing classic ceramic glaze chemistry. It has been used around the world since the early 1980s. Details A glaze chemistry desktop application for Windows, Linux,…
• Digitalfire Insight-LiveDigitalfire Insight-Live A cloud-hosted ceramics-targeted LIMS (lab info management system). It does glaze chemistry and physical testing the “Digitalfire way”. For technicians, educators, potters and hobbyists. Details Digitalfire…
• Digitalfire Reference LibraryDigitalfire Reference Library A public ad-free, no-tracking, technical reference website for potters, educators, technicians and hobbyists in pottery and ceramic production. Since 2000. It is an SEO and AEO success story. Details The…
• Digitalfire TaxonomyDigitalfire Taxonomy One of the biggest strengths of the Digitalfire Reference Library is its taxonomy. It is based on the concept that adjustment, formulation and troubleshooting challenges in ceramics must be approached on the right…
• Dimpled glazeDimpled glaze A ceramic glaze defect characterized by tiny holes in the surface, often too small to see with the naked eye. Details 'Dimpled' glaze surfaces are those that have tiny holes that do not go down to the ceramic underneath (a…
• Dinnerware SafeDinnerware Safe In pottery, the terms dinnerware safe and food safe, are not the same. Perhaps the best way to understand the former is to consider what the opposite might be. Details Dinnerware safety of glazes means something different…
• Dip GlazingDip Glazing A method of applying glaze quickly and evenly to pottery. Details The best way to apply pottery and ceramic glazes in an even layer is by dipping. Many hobbyists and even potters these days apply glazes by brushing. Many of…
• Dipping GlazeDipping Glaze In traditional ceramics and pottery dipping glazes can be of two main types: For single layer and for application of other layers overtop. Understanding the difference is important. Details Dipping (or pouring and draining)…
• Dishwasher SafeDishwasher Safe Dishwasher safety is a concern in ceramic table ware, especially if the ware has been imported or made by a small company or potter. Details Dishwasher safe ceramic ware is generally ware that is not overly absorbent and…
• DisplacerDisplacer Displacers are used to minimize the amount of plaster or rubber needed to make a block or case mold for ceramics. Details The advent of 3D printing for making molds in ceramics has enabled the design of more complex and…
• Do-It-YourselfDo-It-Yourself In the past, all potters were do-it-yourselfers. Now DIY thinking is often being mocked. Has the pendulum swung so far the other way that we are learning helplessness and trading independence for convenience? Details DIY…
• Drop-and-Soak FiringDrop-and-Soak Firing A kiln firing schedule where temperature is eased to the top, then dropped quickly and held at a temperature 100-200F lower. Details Rather than soak (or hold) a kiln at top temperature during a firing, the concept…
• Drying CrackDrying Crack During drying clays and porcelains shrink as they become rigid. When this occurs unevenly, cracks are the result. Details Cracks form to relieve stresses. Plenty of stresses occur while ceramic clays dry. This is because they…
• Drying PerformanceDrying Performance In ceramics, drying performance is very important to optimizing production. More plastic clays shrink more and crack more, but they are also better to work with. Details Refers to the ability of a clay to dry without…
• Drying ShrinkageDrying Shrinkage Clays used in ceramics shrink when they dry because of particle packing that occurs as inter-particle water evaporates. Excessive or uneven shrinkage causes cracks. Details All clays shrink during drying from their wet…
• DuntingDunting Dunting generally refers to firing cracks that occur in ceramic ware as it is cooled in the kiln. The reason is generally uneven cross section or too rapid cooling. Details Dunting is cracking associated with too rapid a cool-down…
• Dust PressingDust Pressing Many ceramic products, especially tile, are formed by pressing high-moisture or binder-containing dust or pelletized dust into steel molds at high pressures. Details A method of fabricating ceramic objects (typically brick,…
• EarthenwareEarthenware What is the difference between earthenware and a regular stoneware body? Earthenwares lack the glass development to fill voids and glue particles. Details A clay fired at low temperatures (cone 010-04). Earthenwares are natural…
• EfflorescenceEfflorescence A common problem with dry and fired ceramic. It is evident by the presence of a light or dark colored scum on the dry or fired surface. Details A term describing the whitish or brownish dry or glassy scum (depending on iron…
• Encapsulated StainEncapsulated Stain This is a type of stain manufacture that enables the use of metal oxides (like cadmium) under temperature conditions in which they would normally fail. Details Encapsulated stains (also called inclusion stains) are a…
• EngobeEngobe Engobes are high-clay slurries that are applied to leather hard or dry ceramics. They fire opaque and are used for functional or decorative purposes. They are formulated to match the firing shrinkage and thermal expansion of the…
• EutecticEutectic In ceramics, this term refers to certain chemistries that melt at much-lower-than-expected temperatures. Details The lowest temperature at which a simple mix of oxides will melt and react to form a transparent glass. Mixtures of…
• Fast Fire GlazesFast Fire Glazes Industrial ceramics are fired very quickly and require minimal micro bubbles and zero pinholes and blisters. Fast fire late melting glazes accomplish that. Details Fast fire glazes are used in most industries and many can…
• Fat GlazeFat Glaze The term 'fat' usually refers to a silky matte glaze that is opaque, thick and pleasant and soft to the touch (sometimes referred to as 'waxy' in texture). The micro surface is wavy rather than flat. The classic fat glaze is a…
• FDM, SLA, SLS, MEX 3D printing technologiesFDM, SLA, SLS, MEX 3D printing technologies Knowing a little about the main types of 3D printing technologies can help you decide which road to take. Details Fused deposition modelling ( FDM ), also known as fused filament fabrication…
• Feldspar GlazesFeldspar Glazes Feldspar is a natural mineral that, by itself, is the most similar to a high temperature stoneware glaze. Thus it is common to see alot of it in glaze recipes. Actually, too much. Details Quite simply, feldspar glazes are…
• Filter PressFilter Press The filter press is one of the most important, and least glamorous, machines in the modern ceramics industry. Potters often imagine clay being dug from the ground and shaped into ware, but industrial ceramic production can…
• Fining AgentFining Agent Individual tiny bubbles in a glaze melt can coalesce around the undissolved particles of a fining agent, the growing bubble swallowing others around it and finally exiting at the surface. Details "Fining" is a term used in…
• FirebrickFirebrick In the ceramic industry, these are the bricks used to build kilns. This term grows out of their ability to withstand high temperatures that would melt or deform structural bricks. Details A brick capable of withstanding high…
• FireclayFireclay A clay that withstands fire. In the ceramics industry, clays that are resistant to deforming and melting at high temperatures are called fireclays. Kiln bricks are often made from fireclay. Details A refractory naturally occurring…
• Fired StrengthFired Strength Ceramics, by their brittle nature, have high compressive strength and unsurpassed surface hardness. Maximum fired strength can come at the expense of various working and fired properties, so testing is needed to reach a…
• Firing ScheduleFiring Schedule Designing a good kiln firing schedule for your ware is a very important, and often overlooked factor for obtained successful firings. Details In industry firing cycles are very fast, measured in minutes, cost and…
• Firing ShrinkageFiring Shrinkage During drying, clay particles draw together and shrinkage occurs. During firing the matrix densifies and shrinkage continues. More vitreous bodies shrink more. Details As kiln temperature increases bodies densify…
• FlamewareFlameware Flameware is ceramic that can withstand sudden temperature changes without cracking. The low thermal expansion of true flameware makes craze-free glazes very difficult. Details Flameware is ceramic that can withstand sudden…
• FlashingFlashing A visual effect that occurs in wood and salt firing of ceramic ware. Many potters value the effect and use special materials and firing methods to enhance it. Details Soda fired porcelain vessel by Heather Lepp ceramics flashing…
• FlocculationFlocculation The flocculation process enables technicians in ceramics to create an engobe or glaze slurry that gels and goes on to ware in a thick yet even, non-dripping layer. Details Technically, flocculation is particle aggregation in a…
• Fluid Melt GlazesFluid Melt Glazes Fluid melt glazes and over-melting, over fired, to the point that they run down off ware. This feature enables the development of super-floss and cyrstallization. Details Fluid melt glazes have a melt that is fluid - many…
• FluxFlux Fluxes are the reason we can fire clay bodies and glazes in common kilns, they make glazes melt and bodies vitrify at lower temperatures. Details On the theoretical glaze chemistry level, a flux is an oxide that lowers the melting or…
• Food SafeFood Safe Be skeptical of claims of food safety from potters who cannot explain or demonstrate why. Investigate the basis of manufacturer claims and labelling and the actual use to which their products are put. Details In recent years…
• Foot RingFoot Ring Footrings, as opposed to flat bottomed containers, lift the piece off the table and enable glazing all of the bottom. While foot rings add extra effort to the finishing stage at fabrication, they also make it easier to glaze the…
• Forming MethodForming Method Refers to the method by which a ceramic component or object is created or manufactured. Common traditional ceramics forming methods include dusting/die pressing, jiggering/jolleying, slip casting , extrusion, ram pressing,…
• Formula RatiosFormula Ratios The ratios of individual or group oxide molecule numbers are indicators of things like fired gloss, durability, melting temperature, balance, tendency to craze, etc. Details Conceptually we consider fired glazes as having a…
• Formula WeightFormula Weight In ceramics , this is the total weight of oxides in an oxide formula (a formula normally expresses the chemistry of a fired glaze, without the LOI present in the unfired raw materials). Since an oxide formula compares…
• FritFrit Frits are used in ceramic glazes for a wide range of reasons. They are man-made glass powders of controlled chemistry with many advantages over raw materials. Details A ceramic glass that has been premixed from raw powdered minerals…
• FritwareFritware A porcelain with significant added frit. The frit matures it at a far lower temperature than typical. The strength mechanism is one of particle glass bonding rather than mullite development. Details Zero3 fritware compared to a…
• FunctionalFunctional A term used in ceramic to express the degree to which an item is safe and stands up to everyday use. Functionality embodies strength, hardness, resistance to acid attack and thermal shock, etc. Details A functional clay body is…
• GHS Safety Data SheetsGHS Safety Data Sheets The Globally Harmonized System (GHS) of classifying and labelling chemicals presents material hazard information in a 16-section user-friendly data sheet. Details The UN Globally Harmonized System of Classification…
• Glass vs. CrystallineGlass vs. Crystalline In ceramics, understanding the difference between what a glass and crystal are provides the basis for understanding the physical presence of glazes and clay bodies. Details In ceramic technology the term 'glass' is…
• Glass-Ceramic GlazesGlass-Ceramic Glazes Glass-ceramic frits are made by the controlled devitrification ( crystallization ) of a composition to create a homogeneous structure in a glassy matrix. Glaze employing these crystalline frits have improved hardness.…
• Glaze BlistersGlaze Blisters Blistering is a common surface defect that occurs with ceramic glazes. The problem emerges from the kiln and can occur erratically in production. And be difficult to solve. Details The principal home of information on this…
• Glaze BubblesGlaze Bubbles Suspended micro-bubbles in ceramic glazes affect their transparency and depth. Sometimes they add to to aesthetics. Often not. What causes them and what to do to remove them. Details As glazes melt, gases from the…
• Glaze ChemistryGlaze Chemistry Glaze chemistry is the study of how the oxide chemistry of glazes relate to the way they fire. It accounts for color, surface, hardness, texture, melting temperature, thermal expansion, etc. Details The chemistry of a glaze…
• Glaze CompressionGlaze Compression In ceramics, glazes are under compression when they have a lower thermal expansion than the body. A little compression strengthens ware, too much can weaken and even fracture it. Details Every solid has a coefficient of…
• Glaze CrawlingGlaze Crawling A ceramic glaze fault that occurs during firing of the ware, the molten glaze pulls itself into islands leaving bare patches of body between. Details The principal home of information on this issue is in the troubleshooting…
• Glaze CrazingGlaze Crazing Crazed ceramic glazes have a network of cracks. Understanding the causes is the most practical way to solve it. 95% of the time the solution is to adjust the thermal expansion of the glaze. Details Crazing is the opposite of…
• Glaze DurabilityGlaze Durability Ceramic glazes vary widely in their resistance to wear and leaching by acids and bases. The principle factors that determine durability are the glaze chemistry and firing temperature. Details Ceramic glazes vary widely in…
• Glaze fitGlaze fit In ceramics, glaze fit refers to the thermal expansion compatibility between glaze and clay body. When the fit is not good the glaze forms a crack pattern or flakes off on contours. Details The relationship between the thermal…
• Glaze GellingGlaze Gelling Glaze slurries can gel if they contain soluble materials that flocculate the suspension. Gelling is a real problem since it requires water additions that increase shrinkage. Details Glaze slurries can gel if they contain…
• Glaze laydownGlaze laydown Refers to the quality of the dried ceramic glaze layer and how this affects the fired result: e.g. density, hardness, evenness, thickness, freedom from defects, etc. Details In industrial ceramics , the quality and evenness…
• Glaze LayeringGlaze Layering In hobby ceramics and pottery it is common to layer glazes for visual effects. Using brush-on glazes it is easy. But how to do it with dipping glazes? Or apply brush-ons on to dipped base coats? Details In hobby ceramics (at…
• Glaze MixingGlaze Mixing In ceramics, glazes are developed and mixed as recipes of made-made and natural powdered materials. Many potters mix their own, you can to. There are many advantages. Details Potters in affluent places in the world have…
• Glaze RecipesGlaze Recipes Stop! Think! Do not get addicted to the trafficking in online glaze recipes. Learn to make your own or adjust/adapt/fix what you find online. Details Warning about recipes that you find online: Be careful about wasting your…
• Glaze shiveringGlaze shivering Shivering is a ceramic glaze defect that results in tiny flakes of glaze peeling off edges of ceramic ware. It happens because the thermal expansion of the body is too much higher than the glaze. Details A defect in glazed…
• Glaze ShrinkageGlaze Shrinkage Raw ceramic glazes contain clay to harden them on drying and to suspend the slurry. The more clay there is the more the glaze shrinks as it dries on the piece. Details Almost all glazes contain clay (e.g. kaolin , ball clay…
• Glaze thicknessGlaze thickness Many ceramic glaze benefits and issues are closely related to the thickness with which the glaze is applied. Many glazes are very sensitive to thickness, so control is needed. Details Simple example of…
• Globally Harmonized Data SheetsGlobally Harmonized Data Sheets GHS Details Related Information Health warning phrases on a bag of Kaolin This picture has its own page with more detail, click here to see it. Health warning phrases on a bag of ball clay This picture has…
• Glossy GlazeGlossy Glaze 'Gloss' refers to how shiny and light-reflective a glaze is. Glazes high in glass former ( SiO 2 , B 2 O 3 ) are glossy. Those high in Al 2 O 3 tend to be matte. Fluid glazes can crystallize to a matte surface if cooled slowly…
• Green StrengthGreen Strength The green strength of clay bodies is an important property, it makes them resistant to breakage or damage during handling in production. Details This refers to the strength of the clay body in the dried form (greenware). The…
• GrogGrog Grog is a term used in ceramics to describe crushed brick (or other fired ceramic) aggregate that is added to sculpture and structural clays to improve drying properties. Details A granular material made from crushed brick, refractory…
• Gunmetal glazeGunmetal glaze A type of ceramic glaze: Pebbly matte black. For functional surfaces, it has enough glossy to not cutlery mark and be easy to clean. Details Refers to a black matte glaze that resembles the pebbly surface of cast iron.…
• Hand Building TechniquesHand Building Techniques Industrious potters around the world have amazing techniques to form pottery, tile and other utilitarian items using primitive home made equipment. Many work without even having a table. Related Information Joining…
• High Temperature GlazeHigh Temperature Glaze In traditional functional ceramics , this term generally refers to glazes that mature at cone 8 and higher. At these temperatures, natural minerals like feldspar , calcium carbonate , etc can be compounded to create…
• Hot PressingHot Pressing Hot pressing is a process used to fabricate ceramic parts (often from non-oxide powders like BIN, SiC or B4C). The process involves the simultaneous application of pressure and heat to a 'green' component or powder under a…
• Incised decorationIncised decoration A type of decoration done on pottery. Designs are carved into the surface of the leather hard ware and often covered by a thickness sensitive glaze. Details In pottery and ceramics , incised decoration is carved into…
• Industrial clay bodyIndustrial clay body Clay bodies used in industry are not somehow magically better than those used in hobby, pottery and education. They are simply more closely tuned to the forming machinery and process. Their formulations prioritize the…
• Infill and SupportInfill and Support Infill and support are structural elements that 3D slicer software uses (e.g. to fill the interior of solid parts or support contours over empty space) Details When solid models are 3D printed they are not typically…
• Ink Jet PrintingInk Jet Printing Ink jet printed decoration is now pervasive in all parts of the ceramic industry. And in hobby also. Details Inkjet equipment and inks are now big business in ceramics , a renaissance in decoration. At this time this page…
• Inside-only GlazingInside-only Glazing Related Information At first I was wondering why those two mugs cracked so badly This picture has its own page with more detail, click here to see it. But actually, I should be wondering why that one did not crack! This…
• Iron Red GlazeIron Red Glaze A type of ceramic glaze, typically fired around 2200F, where iron oxide in the cooling glass precipitates out to form a striking red crystalline mesh on the surface. Details A cone 6 oxidation iron red glaze Iron reds were…
• Jasper WareJasper Ware A porcelain manufacturing technique developed by English potter Josiah Wedgwood in 1775. His ware was typically a blue stained unglazed porcelain with intricately overlaid relief designs on a white unglazed porcelain. The term…
• JiggeringJiggering Jiggering is a process of forming pottery that employs a spinning plaster mold and a tapered template to press soft clay or porcelain against it. Details Finished bowl jigger mold encased in a PLA 3D print This is much more…
• JSONJSON JavaScript Object Notation ( JSON ) represents data as key–value pairs, arrays, and nested structures, making it easy for both humans to read and machines to parse. JSON is text-based, language-independent, and widely supported across…
• KakiKaki Kaki (persimmon) glazes are high fired reduction transparents with a generous supply of iron oxide (12% or more) which forms a microcrystalline surface. If cooled correctly they exhibit "red" coloration. The atmosphere during cooling…
• Kiln ControllerKiln Controller In ceramic kilns the firing schedule is typically managed automatically by an electronic controller. But that may not mean that ware gets automatically fired to the correct temperature and atmosphere. Details An electronic…
• Kiln FiringKiln Firing All types of ceramic are fired in a kiln to cement particles together to produce a hard and water and temperature resistant product. Details At it most basic level, firing is a process of heating a clay (or recipe of clays and…
• Kiln fumesKiln fumes Ceramic kilns fire at very high temperatures and the clays and glazes inside can contain a wide range of materials that produce fumes when heated. Details Fumes can be produced when a clay or glaze decomposes during heat-up in…
• Kiln venting systemKiln venting system Kilns vents are hoods with an exhaust fan that are suspended above an electric kiln. They suck air from around the kiln and expel it through a hose to the outside. Some vents also suck air through a hole in the bottom…
• Kiln WashKiln Wash A high-melting powder applied to kiln shelves to prevent ware from sticking to the shelf during firing. It is also used as a parting agent for to keep elements of fired ware from sticking to each other. Details A refractory…
• Kneading clayKneading clay Wedging (or kneading ) are an age-old process used to mix soft plastic clay and prepare it for use in throwing or hand building. The process is extremely effective in making the softness and color of a lump of clay completely…
• Kovar MetalKovar Metal Kovar metal is thermal expansion compatible with borate glazes. You can actually glaze and fire it like pottery at cone 05, 06! Details Kovar metal has a thermal expansion to which a borosilicate glass can be matched. The match…
• LaminationsLaminations Laminations because of improper pugging of a clay body will cause separations and drying cracks in the ware. Details Laminations are planes of weakly connected material in the plastic matrix of a clay body . Improper pugging or…
• LeachingLeaching Ceramic glazes can leach heavy metals into food and drink. This subject is not complex, there are many things anyone can do to deal with this issue Details Ceramic glazes are not as universally inert and stable as many people…
• Lead in Ceramic GlazesLead in Ceramic Glazes Lead is a melter in ceramic glazes and performs exceptionally well and must be misused to be toxic. It is also now environmentally pervasive. It is toxic and cumulative at any level of exposure. Details Lead is a…
• Leather hardLeather hard Partially dried clayware. Leather hard pieces can still be trimmed, fettled and are still flexible enough that pieces that have gone slightly out-of-round, for example, can be squeezed carefully back into shape. Engobe and…
• Limit FormulaLimit Formula A way of establishing guideline for each oxide in the chemistry for different ceramic glaze types. Understanding the roles of each oxide and the limits of this approach are a key to effectively using these guidelines. Details…
• Limit RecipeLimit Recipe "Recipe logic" is the ability to sanity-check ceramic glaze recipes on sight, by noting that materials present and their relative percentages. Details A " limit recipe " is a sanity check . It is " recipe logic ". The concept…
• Liner GlazeLiner Glaze Liner-glazing is a way to assure that your ware has a durable and leach resistant surface. It also signals to customers that you care about this. Details The term " liner glaze " refers to two things. First, it is a technique…
• Liner GlazingLiner Glazing Step-by-step to apply inside and outside glazes to a pottery mug and get them to meet at a clean line at the rim. Details Mug has been liner glazed , waxed and cut/trimmed but not yet sponge-cleaned for dipping the outer…
• Liquid Bright ColorsLiquid Bright Colors Ceramic lustres are precious metals in liquid form that can be painted on to fired ceramic surfaces to produce metallic and iridescent effects. Details Liquid bright precious metal colors are micro-thin coatings,…
• LOILOI Loss on Ignition is a number that appears on the data sheets of ceramic materials. It refers to the amount of weight the material loses as it decomposes to release water vapor and various gases during firing. Details Simplistically,…
• Low Temperature GlazeLow Temperature Glaze In ceramics, glazes are loosely classified as low, medium and high temperature. Low temperature is in the cone 06-2 range (about 1800F-2000F). Details This term generally refers to glazes that mature from cone 06-04.…
• lustresError 404 Got a Question? https://digitalfire.com
• Magnesia MatteMagnesia Matte Magnesia matte ceramic glazes are “microstructure mattes” while calcia mattes are “crystal mattes”. They have a micro-wrinkle surface that forms from a high viscosity melt and microscopic phase separation, both of which…
• MajolicaMajolica Majolica is a tradition of Italian Renaissance white opaque glazed red earthenware having brightly colored brushwork decoration. Knowing some technical details will help you better succeed with the process. Details Majolica is a…
• making your own glazesError 404 Got a Question? https://digitalfire.com
• Managed Service ProviderManaged Service Provider A Managed Service Provider ( MSP ) is a company that remotely manages a business’s IT infrastructure, systems, and services on an ongoing basis, typically through a subscription or service contract. Rather than…
• MarblingMarbling In ceramics, bodies of different colours can be kneaded together to produce a marble-like result. But caution is needed. Details The practice of partially kneading together clay bodies of contrasting colors (often porcelains…
• Material SubstitutionMaterial Substitution Material substitutions in ceramic glaze and body recipes must consider their chemistry, mineralogy and physical properties Details Material substitution is a constant and ongoing part of any ceramic enterprise that is…
• Matte GlazeMatte Glaze Random material mixes that melt well overwhelmingly want to be glossy, creating a matte glaze that is also functional is not an easy task. Details A glaze that is not glossy. Of course, unmelted glazes will not be glossy, but…
• MaturityMaturity A term used in the ceramics industry to signify the degree of vitrification in a fired clay. Mature clays are dense and strong, immature ones porous and weak. Details A term referring to the degree to which a clay or glaze has…
• Maximum DensityMaximum Density As ceramic bodies vitrify in the kiln they become more dense with temperature (shrinking in the process). A wide range of particle types typically exist and they react to heat differently. Some melt and flow. Some alter…
• MDTMDT An acronym for Materials Definition Table. The XML materials database of Digitalfire Insight glaze chemistry software. Details MDT is an acronym for Materials Definition Table. It is the materials database of Digitalfire Insight glaze…
• Medium TemperatureMedium Temperature These are stoneware glazes that fire in the range of 1200C (2200F). They often contain boron to assist with melting. Details In functional ceramics , this term generally refers to glazes and bodies that mature from cone…
• Melt FluidityMelt Fluidity Ceramic glazes melt and flow according to their chemistry, particle size and mineralogy. Observing and measuring the nature and amount of flow is important in understanding them. Details Glazes become fluid when they melt,…
• Melting TemperatureMelting Temperature The melting temperature of ceramic glazes is a product of many complex factors. The manner of melting can be a slow softening or a sudden liquifying. Details Unlike crystalline minerals, glazes do not have a specific…
• Metal OxidesMetal Oxides Metal oxide powders are used in ceramics to produce color. But a life time is not enough to study the complexities of their use and potential in glazes, engobes, bodies and enamels. Details Metal oxides are what the name…
• Metallic GlazesMetallic Glazes Non-functional ceramic glazes having very high percentages of metallic oxides/carbonates (manganese, copper, cobalt, chrome). Details Metallic glazes can most easily be produced in oxidation by mixing a very high percentage…
• Micro OrganismsMicro Organisms Ceramic glazes and clay bodies can host micro organisms. They can be just a nuisance, a source of worry or can render a product useless. What should you do? Details Every potter has had the experience of opening a bucket of…
• Microwave SafeMicrowave Safe Microwave safety is a concern in the production of function ceramic ware. Details The most obvious problem almost everyone has seen is the failure of gold decorated bone china in the oven. This is because conducting metals…
• Mineral phaseMineral phase A 'phase' of a mineral is a physically different molecular or crystal structure induced by a set of conditions (i.e. temperature, pressure). Phases of silica , for example, are chemically the same but have different physical…
• MineralogyMineralogy Raw ceramic materials are minerals or mixtures of minerals. By taking the characteristics of these into account technicians can rationalize the application of glaze chemistry. Details Ceramic raw materials are mostly studied at…
• Mocha glazesMocha glazes A technique used by ceramic artists to decorate pottery. It happens when bleeding occurs at the edges of a thin colored acidic mixture painted over a still-wet slip. Details Mocha diffusion is a technique of layering slips…
• Mohs HardnessMohs Hardness Hardness is measured on the Moh's hardness scale. Each of the values is a naturally occuring mineral. Testing devices (e.g. pencils) mount these in the tip. 10 Diamond 9 Corundum 8 Topaz 7 Quartz 6 Feldspar 5 Apatite 4…
• Mold NatchesMold Natches At digitalfire we are big fans of slip casting and want to help people and companies (even hobbyists) to integrate it into their production. Details 3D design and 3D printing are enabling a rethink of almost every detail of…
• Mold Shell FlangeMold Shell Flange Learning to create flanges in CAD design enables a new kind of DIY mold-making for ceramics: 3D-printed lightweight reusable molds that clamp together. Details Many issues must be dealt with when using consumer 3D…
• Mole%Mole% Mole% is a way of expressing the oxide formula of a fired glaze or glass. It is a preferred over the formula by many technicians who use glaze or glass chemistry. Details Mole% is a way of expressing the oxide formula of a fired…
• MonocotturaMonocottura The single-firing process (as opposed to Bicottura which fires twice or more times) of making tile from terra cotta clay and firing it high enough to achieve a strong and dense product. Normally and engobe layer is applied over…
• Mosaic TileMosaic Tile While traditional mosaic imagery have been created from small pieces of glass or stone, computerized equipment is making it increasingly practical to create the pieces from clay or porcelain Details More information coming on…
• MottledMottled See Variegated. Got a Question? https://digitalfire.com
• Native ClayNative Clay A clay that a potter finds, tests and learns to process and use himself. To reduce the costs of importing materials manufacturers, especially in Asia, often develop processes for clays mined in their locality. Details This is…
• Non Oxide CeramicsNon Oxide Ceramics Fired ceramic that contains no oxygen in the crystal structure. Examples are boron nitride (BN) and silicon barbide (SiC). Hundreds of different types of these materials exist (dozens of boron derivatives alone). These…
• Oil-spot glazeOil-spot glaze A mottled glaze created by double-layering glazes of different melt fluidity and color Details Officially, the oil-spot variegation effect appears to be the product of bubble generation associated with the release of gases…
• Once fire glazingOnce fire glazing Refers to the practice of firing ceramics in one firing (rather than two) to produce a fully glazed product. This practice requires more technical expertise. Details The practice of applying glazes to dried ware and…
• OpacifierOpacifier Glaze opacity refers to the degree to which it is opaque. Opacifiers are powders added to transparent ceramic glazes to make them opaque. Details A glaze additive that impart opacity , transforming an otherwise transparent glaze…
• OpacityOpacity Opacity of ceramics glazes is normally achieved by adding an opacifier like tin oxide or zircon. However, there are chemical profiles that can turn transparent glazes milky and make it cheaper to opacify them. Details Ceramic glaze…
• OvenwareOvenware Ovenware clay bodies have a low expansion by virtue of materials in their recipe and/or the way they are fired. But potters bend the rules. Details Ovenware clay bodies have a lower thermal expansion than typical bodies so they…
• OverglazeOverglaze A method of applying decoration over the glaze surface of ceramics. It can be done before or after the glaze firing. Details 'Onglaze' decoration can refer to two very different processes. The first involves the application of…
• Oxidation FiringOxidation Firing In ceramics, this term is most often used to refer to kilns firing with an atmosphere having available oxygen to react with glaze and body surfaces during firing Details A firing where the atmosphere inside the kiln has…
• Oxide FormulaOxide Formula In ceramics, the chemistry of fired glazes is expressed as an oxide formula. There are direct links between the oxide chemistry and the fired physical properties. Details Conceptually we consider fired ceramic glazes as being…
• Oxide InteractionOxide Interaction In ceramic glazes each oxide generally makes a specific contributions to the melting and freezing behavior of the glaze. However interactions are also important. Details In a glaze melt, oxides do not act alone, they…
• Oxide SystemOxide System In ceramic glaze calculation, a 'system' refers to a collection of glaze recipes that share a common set of oxides and material types (e.g. cone 10 dolomite mattes, cone 06 fritted boron glossies, cone 6 alumina matte, cone…
• Particle classificationParticle classification A process control mechanism to enable control of grinding efficiency, equipment wear and material quality. Details The term " particle classification " can refer to a strategic process control mechanism , used in…
• Particle orientationParticle orientation Ceramic clays have a flat particle shape. Various factors determine the extent to which they can bind face-to-face in pugged clay in the presence of particles of other materials. Details Clay particles are flat and…
• Particle Size DistributionParticle Size Distribution Knowing the distribution of particle sizes in a ceramic material is often very important in assessing its function and suitability for an application. Details When minerals and mixtures of minerals are ground…
• Particle size reductionParticle size reduction Ceramic materials that we receive as powders have to be crushed and dried, and then ground into fine powders. Many types of equipment are used for this. Details Pulverization of ceramic materials, especially clays,…
• Particle SizesParticle Sizes Knowledge of the physical and ultimate particles sizes in ceramic minerals and materials is an important part of understanding them, predicting their usefulness and explaining their behavior. Details In ceramics , discussion…
• PCEPCE Pyrometric Cone Equivalent A measure of how refractory a material is. The measure is done by making a small cone from the material and firing it till it bends. A typical stoneware clay body , for example, might have a PCE of cone 20.…
• PermeabilityPermeability In ceramics, the permeability of clay slurries and plastics determines the rate as which water can move through the matrix Details The term " permeability " can occur in multiple contexts in ceramics . Most often it refers to…
• Phase DiagramPhase Diagram A triangular chart showing graphically the development of different phases across different tempertatures for mixtures of three oxides or oxide blends. Related Information Phase diagram of a SiO2:Al2O3:CaO:KNaO System This…
• Phase SeparationPhase Separation Phase separation in glaze melts creates microscopic discontinuities that affect transparency, color variegation, matte surfaces, and reactive glaze effects. Details Phase separation occurs when a molten glaze does not…
• Physical TestingPhysical Testing In ceramics, glazes, engobes and bodies have chemistries and physics. Your formulation and quality control most likely need to focus on the physical properties. Details In many ceramic circles today, the chemistry of…
• PinholingPinholing Pinholing is a common surface defect that occurs with ceramic glazes. The problem emerges from the kiln and can occur erratically in production. Details A glaze defect where tiny holes are present in the fired glaze surface.…
• Plainsman ClaysPlainsman Clays A clay mining and processing company in Southern Alberta since 1965. Details A small clay mining and processing company located in Medicine Hat, Alberta, Canada. Plainsman makes dry and pugged clay bodies for potters,…
• Plaster BatPlaster Bat Plaster bats are a key tool used by many potters. But their true value is not understood by most: They produce ware with much less cracking problems Details Plaster bats are employed primarily for making pottery on a potters…
• Plaster tablePlaster table Essential in a pottery studio for dewatering reclaim clay, stiffening clay that is too soft or making your own clay bodies. Details Every serious potter, studio, school and lab needs a plaster table . The bigger the better.…
• PlasticinePlasticine Plasticine is an oil-based modeling material that feels superficially like pottery clay but behaves very differently. Unlike ceramic clay, it does not dry by water evaporation, does not harden on standing and cannot be fired in…
• PlasticityPlasticity Plasticity (in ceramics) is a property exhibited by soft clay. Force exerted effects a change in shape and the clay exhibits no tendency to return to the old shape. Elasticity is the opposite. Details This term is used in…
• PluckingPlucking A firing issue in ceramics where the foot rings of vitreous ware stick to the kiln shelf. Removing them leaves sharp fragments glued to the shelf. Details Plucking refers to the chipping away of small fragments of the base of a…
• PorcelainPorcelain How do you make porcelain? There is a surprisingly simple logic to formulating them and to adjusting their working, drying, glazing and firing properties for different purposes. Details A " mullite porcelain " pottery mug and an…
• Porcelain InsulatorsPorcelain Insulators Among the most difficult ceramic product to make. They demand electrical reliability, mechanical strength, weather resistance, and dimensional consistency over decades of outdoor service. Details Electrical porcelain…
• Porcelaineous StonewarePorcelaineous Stoneware In ceramics, porcelains lack plasticity and fire to high density with white, glassy surface. Stonewares are plastic and fire cream to brown and lower density, Porcelaineous stoneware are between these two. Details…
• Portable Document FormatPortable Document Format A Portable Document Format ( PDF ) is a universal file format developed to present documents consistently across different devices, operating systems, and software. Unlike word processor files or web pages, a PDF…
• Pour GlazingPour Glazing A method of applying glaze evenly and quickly to pottery. Details In recent years hobby and even professional potters are been switching to buying bottled glazes and applying them by brush. They deem this worthwhile for the…
• Pour SpoutPour Spout Plaster molds intended for slip casting have a spare at the top to act as a reservoir. This enables overfilling the mold to accommodate the dropping slurry level. 3D-printed spouts make a spare unnecessary. Details Two handle…
• Powder ProcessingPowder Processing An entire industry is dedicated to the science, materials and equipment associated with the creation, processing and handling of powders. Details An entire industry is dedicated to the science, materials and equipment…
• PrecipitationPrecipitation Crystals or crystalline particles will often form over time in ceramic glaze slurries that contain slightly soluble materials. Details If a glaze slurry contains soluble or partially soluble raw materials or is made using…
• Primary ClayPrimary Clay A clay deposit that is near the site of erosion and alteration. They have more mechanical impurities and fewer chemical and mineralogical impurities. Primary clays have larger particles and less plasticity. Details Kaolinite…
• Primitive FiringPrimitive Firing The use of some traditional firing techniques is still popular among modern potters and sculptors (who are accustomed electric and gas kilns, often with computer controllers). Details Most potters and sculptors fire in…
• PropanePropane Propane fired gas commercial and home-built kilns are quite common. However this process seems to generate more questions than any other, especially on the subject of propane tanks. If the propane tank is not large enough, for…
• Propeller MixerPropeller Mixer In ceramic studios, labs and classrooms, a good propeller mixer is essential for mixing glaze and body slurries. Details An important, even essential tool in ceramic labs, studios and classrooms for mixing test and…
• PugmillPugmill The practice of removing air from clay as it is pugged. Deaired clay has better forming properties and produces a smoother fired surface. Details Pugmills have a main chamber with rotating shaft having angled blades. The shaft is…
• PyroceramicsPyroceramics The term is generally used in a generic sense to refer to porcelain tableware that has an extremely low thermal expansion . While " Corning ware ", for example, is a trade secret of Corning Glass Works, it is well known that…
• Pyrometric ConePyrometric Cone Cones are ceramic and bend through a narrow temperature range. They used to be actively used to determine when firings were completed but now are used to calibrate electronic devices. Details A pyramid-shaped ceramic device…
• Quartz InversionQuartz Inversion In ceramics, this refers to the sudden volume change in crystalline quartz particles experience as they pass up and down a temperature window centering on 573C. Details The term " quartz inversion " is used in two ways.…
• RakuRaku Gas fired rustic ceramic ware is cooled from red-hot in a closed container with organic material. The zero-oxygen atmosphere produced reduces carbonate metal decoration to its metallic form. Details The raku process is an economical…
• Reactive GlazesReactive Glazes In ceramics, reactive glazes have variegated surfaces that are a product of more melt fluidity and the presence of opacifiers, crystallizers and phase changers. Details Reactive glazes are variegated, or mottled; they do…
• Reduction FiringReduction Firing A method of firing stoneware where the kiln air intakes and burners are set to restrict or eliminate oxygen in the kiln such that metallic oxides convert to their reduced metallic state. Details The same clay fired in…
• Reduction SpeckleReduction Speckle A sought-after visual effect that occurs in reduction fired stoneware. Particles of iron pyrite that occur naturally in the clay melt and blossom up through the glaze Details An effect created by firing a clay containing…
• Refiring CeramicsRefiring Ceramics Refiring pottery and porcelain comes with many issues that can ruin ware, knowing about these will help you do it successfully. Details Refiring ceramic ware can be a necessity because of the process (e.g. decal , lustre…
• RefractoryRefractory In the ceramic industry, refractory materials are those that can withstand a high temperature without deforming or melting. Or can be sintered into super materials. Details In ceramics , the term “refractory” refers to the…
• Refractory Ceramic CoatingsRefractory Ceramic Coatings These are sprayed on ceramic kiln interiors to improve heat, corrosion and wear resistance. Details Refractory ceramic coatings are sprayed onto the insides of kilns and on elements to achieve several goals.…
• Representative SampleRepresentative Sample In a testing process, it is important that the sample being tested is representative of the entire lot being evaluated. In production, this could be thousands of bags, boxes, tons, etc. Representative samples are…
• Restaurant WareRestaurant Ware If you are a potter and want to make restaurant ware, read this. Many of the things you already think you know will mislead you in this type of venture. Details Ceramics (mostly plates, cups, saucers) used in restaurants…
• RheologyRheology In ceramics, this term refers to the flow and gel properties of a glaze or body suspension (made from water and mineral powders, with possible additives, deflocculants, modifiers). Details Rheology refers to the array of…
• Rutile Blue GlazesRutile Blue Glazes A type of ceramic glaze in which the surface variegates and crystallizes on cooling in the presence of titanium and iron (usually sourced by rutile) Details Many fluid melt glazes will do magic things (e.g. variegate )…
• Salt and Soda firingSalt and Soda firing Salt firing is a process where unglazed ware is fired to high temperatures and salt is introduced to produce a vapor that glazes the ware. Details Plainsman P580, P600 , H570 soda fired samples These are standard…
• Sanitary wareSanitary ware A type of porcelain zircon-glazed ceramic that includes bathtubs, sinks, toilets, etc. Details This is a very large industry worldwide, second only to ceramic tile in clay and energy use. The knowledge of how to make…
• SculptureSculpture In ceramics, clays with added aggregate are free formed or molding into shapes that are slowly dried and fired in a kiln. The process requires much skill. Details More info coming soon. Related Information A sculpture bodies gets…
• Search Engine OptimizationSearch Engine Optimization Traditionally, SEO (Search Engine Optimization) involved optimizing our websites and content to rank higher in search engine results for relevant queries. We have always been successful, with hundreds (or even…
• Secondary ClaySecondary Clay Clays form by the weathering of rock deposits over long periods. Primary clays are found near the site of alteration. Secondary clays are transported by water and laid down in layers. Details Clays that have been transported…
• Shino GlazesShino Glazes Traditional Japanese high feldspar glazes having cream to orange color flashing or blushing. Potters today seek to emulate the Shino appearance using a wide range of recipes. Details Shino glazed small bowl from Japan Shino…
• Side RailsSide Rails Side rails are the containment used when pouring plaster molds. We 3D-print these to custom fit each mold. Details Precise railing is a key to success in mold-making for ceramics . Polycoated cottle boards are traditional for…
• SieveSieve Sieves are important in ceramics for removing particulates and agglomerates from glaze, engobe and body slurries. Details Sieves 325 mesh sieve earthenware stoneware engobes porcelain agglomerates 80 mesh water content 35 mesh: 500…
• Sieve ShakerSieve Shaker A device that can vibrate a sieve thus greatly increasing the speed at which it can process a slurry or powder. Details While sieve shakers are common for processing powders and slurries. To slurry up a clay body , glaze or…
• Silica:Alumina RatioSilica:Alumina Ratio A formula ratio used to evaluate and predict firing properties in ceramic glazes. Details The ratio of silicon dioxide to alumina oxide ( SiO 2 :Al 2 O 3 ratio) is often used as an indicator of glaze matteness. A glaze…
• Silk screen printingSilk screen printing Silk screen printing is one of the best options for hobbyists and potters to reproduce crisp and detailed decoration. But there are many details to know. Details Historically, screen printing has been a popular…
• SinteringSintering A densification process occurring within a ceramic kiln. With increasing temperatures particles pack tighter and tighter together, bonding more and more into a stronger and stronger matrix. Details The term " sintered " refers to…
• SlakingSlaking This term is using in ceramics to describe how a dry clay disintegrates when it is immersed in or exposed to water. Different clays have different slaking rates. Details 'Slaking' refers to the breakdown that normally occurs when…
• Slip CastingSlip Casting A method of forming ceramics. A deflocculated (low water content) slurry is poured into absorbent plaster molds. As it sits in the mold, usually 10+ minutes, a layer builds against the mold walls. When thick enough the mold is…
• Slip TrailingSlip Trailing A technique used by potters to decorate ware. Neutral and colored slips, clay in thick paste form, are trailed onto the ware (in raised lines and strokes) to create tactile designs. Details A technique of adding a relief…
• SlipwareSlipware Slipware, in the UK, is terra cotta pieces decorated at leather hard with thixotropic high ball clay slips, then bisque fired and clear glazed with lead bilisicate. Details The term " Slipware " can refer to a specific pottery…
• SlurrySlurry A slurry is a water-based mix of insoluble mineral and material powders. When the term refers to a ceramic glaze or engobe or a casting clay body , the slurry is also a suspension in which rheological properties are maintained (e.g.…
• Slurry ProcessingSlurry Processing Glaze, engobe and body slurries are suspensions and they are an integral part of ceramic production. In almost all cases slurries can exist because the electrolytic properties of clay particles present create a gel that…
• Slurry UpSlurry Up The process of slurrying a clay body powder and dewatering it on a plastic slab or table. Details In hobby ceramics and pottery, this expression is a verb referring to the preparation of a plastic clay body by weighing out the…
• SoakingSoaking The process of holding a kiln at the final temperature (or at other temperatures) to enable the heat to penetrate the ware or to effect or complete a glaze or body reaction Details The practice of holding the kiln at final firing…
• Soluble colorsSoluble colors Water-soluble salt colors are used in porcelain tile for surface decoration and in automated application systems (inkjet printing). Polyethylene glycol additive may be used to maintain viscosity and CMC gum for binding. In…
• Soluble SaltsSoluble Salts In ceramics, certain compounds in clays and glazes can dissolve into the water, then on drying these are left on the surface. Details In ceramics , certain compounds (e.g. calcium or magnesium sulphate) in clays and glazes…
• Specific gravitySpecific gravity In ceramics, the specific gravity of slurries tells us their water-to-solids ratio. That ratio is a key indicator of performance and enabler of consistency. Details A comparison of the weights of equal volumes of a given…
• SplittingSplitting Refers to a phenomenon where a plastic clay develops cracks and splits open to relieve the self-support stresses it is subjected to. The process often occurs over a period of minutes. This typically happens on the bellies of…
• Spray GlazingSpray Glazing In ceramic industry glazes are often sprayed, especially in sanitary ware. The technique is important. Details In the production of smaller bisque fired ceramics it is almost always possible to dip-glaze ware. However, this…
• Stain MediumStain Medium It is a mistake to use pure stains for decorating ware. Stains need to be mixed with a ceramic carrier and a working medium to work and fire well. Details Ceramic stains are highly concentrated refractory pigment powders.…
• StonewareStoneware To potters, stonewares are simply high temperature, non-white bodies fired to sufficient density to make functional ware that is strong and durable. Details In traditional ceramics , the term " stoneware " refers to a high-fired…
• Stull ChartStull Chart Stull charts attempt to explain graphically, on an x-y coordinate system, specific fired properties of selected mixes of oxides . It is a visual way to understand the relationships between glaze chemistry and fired results. For…
• Sulfate ScumSulfate Scum A yellow coloration can appears on the dry glaze surface, or on the bisque clay surface on the opposite side of a vessel wall that has just been glazed. The coloration does not appear immediately, but some time during the…
• SulfatesSulfates Soluble sulfates in clay produce efflorescence, an unsightly scum that mars the fired surface of structural and functional ceramic products. Details Sodium, potassium, magnesium sulfates can be found in many clays. These are…
• Surface AreaSurface Area The surface area of a powder can be measured. It is the total surface area of all the particles in a gram of the material, and this number can be alot larger than you might think. Details Surface area (or SSA - Specific…
• Surface TensionSurface Tension In ceramics, surface tension is discussed in two contexts: The glaze melt and the glaze suspension. In both, the quality of the glaze surface is impacted. Details Related Information These two transparent glazes are…
• SuspensionSuspension In ceramics, glazes are slurries. They consist of water and undissolved powders kept in suspension by clay particles. You have much more control over the properties than you might think. Details In traditional ceramics , glazes…
• Tapper ClayTapper Clay Tapper clay is used to seal the drain hole in melting vessels used in the smelting industries. Details Tapper clay is used to seal the drain hole in melting vessels in the smelting industries. It is refractory , low in…
• TenmokuTenmoku Tenmoku is a kind of high temperature reduction firing ceramic glaze. Glossy, very dark brown or maroon, fluxed by iron oxide to have high melt fluidity. Details Tenmoku mugs fired at cone 10R . Two different recipes. reduction…
• Terra CottaTerra Cotta A type of red firing pottery. Terra cotta clay is available almost everywhere, it is fired at low temperatures. But quality is deceptively difficult to achieve. Details 'Terra Cotta' (Italian for 'cooked earth') is red-burning…
• Terra SigilattaTerra Sigilatta Terra Sigilatta is a sedimentation process used by potters to remove coarse particles from a clay powder. It enables burnishing and gloss surfaces without the use of glaze. Details Terra Sigilatta is produced using a simple…
• Test KilnTest Kiln A test kiln is a must for all potters and small manufacturers, even serious hobbyists. Here is why. Details A test kiln is a small kiln having the ability to fire to the temperature and firing schedule of your production kiln. It…
• Theoretical MaterialTheoretical Material In glaze chemistry, theoretical materials are used to represent what a material would be if it was uncontaminated and perfectly crystallized Details A material the way it would be if its crystal structure perfectly…
• Thermal ConductivityThermal Conductivity Thermal conductivity is an often quoted property of fired ceramic. It is important when choosing materials that need insulating properties. Details When the insulating properties of ceramic components are important one…
• Thermal shockThermal shock When sudden changes in temperature cause dimensional changes ceramics often fail because of their brittle nature. Yet some ceramics are highly resistant. Details Thermal shock refers to stresses imposed on a ceramic by the…
• ThermocoupleThermocouple A simple probe made from two kinds of wire (i.e. platinum, rhodium) welded together. This probe is wired to a sensitive electronic meter that displays a reading of the voltage it generates when heated. However, the world of…
• ThixotropyThixotropy Thixotropy is a property of ceramic slurries of high water content. Thixotropic suspensions flow when moving but gel after sitting (for a few moments more depending on application). This phenomenon is helpful in getting even,…
• ThrowingThrowing Vase thrown on potters wheel Made from Plainsman M390 clay. Throwing ceramics plasticity physics bentonite Related Information Throwing a pot on a potters wheel This picture has its own page with more detail, click here to see it.…
• Tipping pointTipping point Why do ceramic processes seem to work for years and then suddenly fail? Learn how hidden tipping points in materials and methods can trigger production disasters. Details Hobbyists, potters and even manufacturers often "live…
• Tony HansenTony Hansen Tony Hansen is the author of Digitalfire Insight, Digitalfire Reference Library and Insight-Live.com, he is a long-time potter, ceramic lab-technician and body and glaze developer. Details I am a potter, researcher, author,…
• ToxicityToxicity Common sense can be applied to the safe use of ceramic materials. The obvious dangers are breathing the dust and inhaling the fumes they produce during firing. Here is a round-up of various materials and their obvious hazards.…
• TraffickingTrafficking At Digitalfire we use the term "recipe trafficking" to describe the online trade in ceramic and pottery glaze recipes that can waste your time and cost you lots of money. Better to learn to understand glazes. Details At…
• TranslucencyTranslucency A highly sought-after property in porcelain, fired close enough to melting to take on the glass-like property of passing light. Translucency implies tendency to warp during firing. Details Standard vs Translucent Porcelain…
• Triaxial Glaze BlendingTriaxial Glaze Blending In ceramics many technicians develop and adjust glazes by blending two, three or even four l materials or glazes together to obtain new effects Details An often employed a way to develop new (usually visual) glaze…
• Ultimate ParticlesUltimate Particles Utlimate particles of ceramic materials are finer than can be measured even on a 325 mesh screen. These particles are the key players in the physical presence of the material. Details Processed ceramic materials are…
• UnderglazeUnderglaze Understand pottery underglazes: Why they brush differently, how they fire, why clears fail over them, and how to make your own recipes. In technical rather than art language. Details Underglazes are often described as romantic…
• Unity FormulaUnity Formula The chemistry of ceramic glazes are normally expressed as formulas. A unity formula has been retotaled to make the numbers of flux oxides total one. Details A " unity formula " is just an oxide formula that has been retotaled…
• UpworkUpwork Using the services of online freelancers connects potters and small ceramic producers to expert engineering talent at low cost. Details There are many freelancer websites online, this is the one we know. Services like these, that…
• VariegationVariegation Ceramic glaze variegation refers to its visual character. This is an overview of the various mechanisms to make glazes dance with color, crystals, highlights, speckles, rivulets, etc. Details Multiple kinds of glaze variegation…
• ViscosityViscosity In ceramic slurries (especially casting slips, but also glazes) the degree of fluidity of the suspension is important to its performance. Details The term viscosity is used in ceramics most often to refer to the degree of…
• VitreousVitreous The fired state of a ceramic when sufficient heat in the kiln has produced the density and strength common, and expected, in stonewares and porcelains. Details The term " vitreous " refers to a state (whereas vitrification is a…
• VitrificationVitrification A process that happens in a kiln, the heat and atmosphere mature and develop the clay body until it reaches a density sufficient to impart the level of strength and durability required for the intended purpose. Most often…
• VolatilesVolatiles Compounds with clays or glazes that burn away during firing. For example, calcium carbonate decomposes during firing to produce CO2 gas and loses almost half its weight. Other common volatiles are sulphur, carbon, water,…
• Water ContentWater Content Water content is one of the most important and most misunderstood variables in ceramics . Almost every ceramic process depends on controlling it. Water affects plasticity , drying behavior, shrinkage, density, rheology ,…
• Water in CeramicsWater in Ceramics Water is the most important ceramic material, it is present every body, glaze or engobe and either the enabler or a participant in almost every ceramic process and phenomena. Details There is a need to discuss water in…
• Water SmokingWater Smoking In ceramics, this is the period in the kiln firing where the final mechanical water is being removed. The temperature at which this can be done is higher than you might think. Details Refers to the period in a kiln firing…
• Water SolubilityWater Solubility The water solubility of ceramic materials is an important consideration to their usability in the process. Glazes are suspensions of insert powders, solubles present problems to this system. Details A host of water soluble…
• WedgingWedging The process of mixing a plastic clay by hand before forming it. Similar to kneading of bread dough, it is considered an essential step by most potters. Details Wedging soft, plastic clay is similar to kneading bread dough. Clay…
• WhitewareWhiteware The branch of the ceramic industry that manufactures porcelain toilets and sinks and other utilitarian heavy items used in bath and shower. Details A term used in the ceramic industry to refer to the branch that manufactures…
• WooCommerceWooCommerce An plugin for WordPress the enables converting a website into an electronic store. It is the most popular platform online and is at the center of a huge support industry. Details WooCommerce is an add-on to WordPress to turn a…
• Wood Ash GlazeWood Ash Glaze Common washed wood ash can supply important ceramic oxides when melted, so it can comprise significant percentages in a recipe. Plus it can produce unique visual effects. Details A glaze that employs organic ash (e.g. paper,…
• Wood FiringWood Firing A method of firing pottery in a fuel burning kiln (using wood) rather than gas. Temperatures beyond cone 10 can be achieved. Details These H440 and H550 clays have been fired in a wood kiln. They were unglazed. flashing ash…
• WordPressWordPress A content management system used to create websites. Hundreds of millions of websites use it. Thousands of company create products and training for it. Details The days of consultants charging tens of thousands of dollars for…
• Zero3Zero3 The designation for a group recipes for body, glaze and engobe (by Tony Hansen), that potters can use to make low fire stoneware and fritware porcelain at 1100C (2000F) or cone 03. Details The term " Zero3 " was coined by Tony Hansen…
• Zero4Zero4 The designation for a group recipes for body, glaze and engobe (by Tony Hansen), that potters can use to make low fire stoneware and fritware porcelain Details Zero4 porcelain ( code number L3924J ) is a fritware concept body…
• Zeta PotentialZeta Potential A phenomenon, which when understood, assists technicians to create better deflocculated ceramic slurries. It relates to the understanding the electrolytic interactions of minute particles in a suspension (colloidal science).…