Home
Forgot your password?
Categories
Materials Classification for the Grid Method
This list is to help you categorise your materials when using the grid method, particularly when using the Calculation Page or the Percentage Calculator. Materials that form part of the base glaze (providing part or all of flux, alumina, silica) are marked: (Base Glaze). If you need it, there is more explanation about categories at the bottom of this page.
| Material | Category |
|---|---|
| Albany slip | Flux material (Base Glaze) |
| Alumina | Alumina material (Base Glaze) |
| Alumina hydrate | Alumina material (Base Glaze) |
| Amblygonite | Flux material (Base Glaze) |
| Ball clay | Alumina material (Base Glaze) |
| Barium Carbonate | Flux material (Base Glaze) |
| Barium Sulphate | Flux material (Base Glaze) |
| Basalt | Flux material (Base Glaze) |
| Bauxite | Alumina material (Base Glaze) |
| Bentonite | Additive |
| Bone Ash | Additive or Flux material? (Base Glaze?) |
| Borax | Flux material (Base Glaze) |
| CaCO3 | Flux material (Base Glaze) |
| Calcite | Flux material (Base Glaze) |
| Calcium carbonate | Flux material (Base Glaze) |
| Carboxy methyl cellulose (CMC) | Additive |
| Chalk | Flux material (Base Glaze) |
| China clay | Alumina material (Base Glaze) |
| Chrome oxide | Additive (colourant) |
| Clay | Alumina material (Base Glaze) |
| CMC | Additive |
| Cobalt oxide/carbonate | Additive (colourant) |
| Colemanite | Flux material (Base Glaze) |
| Copper oxide/carbonate | Additive (colourant) |
| Cornwall stone | Flux material (Base Glaze) |
| Diatomite | Silica material (Base Glaze) |
| Diatomaceous earth | Silica material (Base Glaze) |
| Dolomite | Flux material (Base Glaze) |
| Epsom salts | Additive (flocculant, glaze thickener) |
| Erbium oxide | Additive (colourant) |
| Fe2O3 | Additive (colourant) |
| Feldspar | Flux material (Base Glaze) |
| Ferric/ferrous oxides | Additive (colourant) |
| Fireclay | Alumina material (Base Glaze) |
| Flint | Silica material (Base Glaze) |
| Fluorspar | Flux material (Base Glaze) |
| Frit | Flux material (Base Glaze) |
| GerstleyBorate | Flux material (Base Glaze) |
| Glaze | Flux material (Base Glaze) |
| Granite | Flux material (Base Glaze) |
| Ilmenite | Additive (colourant) |
| Iron Oxide | Additive (colourant) |
| K. Feldspar | Flux material (Base Glaze) |
| Kaolin/Kaolinite | Alumina material (Base Glaze) |
| Lead oxide | Flux material (Base Glaze) |
| Lead silicate(s) | Flux material (Base Glaze) |
| Lepidolite | Flux material (Base Glaze) |
| Limestone | Flux material (Base Glaze) |
| Lithium Carbonate | Flux material (Base Glaze) |
| Magnesium Carbonate | Flux material (Base Glaze) |
| Magnesium Carbonate (light) | Flux material (Base Glaze) |
| Manganese oxide/carbonate | Additive (colourant) |
| Na feldspar | Flux material (Base Glaze) |
| Neodymium oxide | Additive (colourant) |
| Nepheline Syenite | Flux material (Base Glaze) |
| Nickel oxide | Additive (colourant) |
| Ochre | Additive (colourant) |
| Petalite | Flux material (Base Glaze) |
| Potash feldspar | Flux material (Base Glaze) |
| Potassium carbonate | Flux material (Base Glaze) |
| Praseodymium oxide | Additive (colourant) |
| Quartz | Silica material (Base Glaze) |
| Red Iron Oxide (RIO) | Additive (colourant) |
| Red ochre | Additive (colourant) |
| Rutile | Additive (opacifier, also colourant) |
| Salt | Flux material (Base Glaze) |
| Silica | Silica material (Base Glaze) |
| Silicon carbide | Additive (reducing agent/bubbling agent) |
| SiO2 | Silica material (Base Glaze) |
| Soda Feldspar | Flux material (Base Glaze) |
| Sodium carbonate | Flux material (Base Glaze) |
| Sodium chloride | Flux material (Base Glaze) |
| Sodium silicate | Additive |
| Spodumene | Flux material (Base Glaze) |
| Strontium Carbonate | Flux material (Base Glaze) |
| Talc | Flux material (Base Glaze) |
| Tin oxide | Additive (opacifier) |
| Titanium dioxide | Additive (opacifier) |
| Uranium oxide | Additive (colourant) |
| Vanadium oxide | Additive (colourant) |
| Washing soda | Flux material (Base Glaze) |
| Whiting | Flux material (Base Glaze) |
| Wollastonite | Flux material (Base Glaze) |
| Wood ash | Flux material (Base Glaze) |
| Yellow ochre | Additive (colourant) |
| Zinc Oxide | Flux material (Base Glaze) |
| Zircon | Additive (opacifier) |
| Zircon opacifier | Additive (opacifier) |
| Zircon silicate | Additive (opacifier) |
| Zirconium oxide | Additive (opacifier) |
Some Notes on Categories for the Grid Method
When using the Grid Method for designing a 35-glaze grid it is necessary to classify your glaze materials into several categories:
Four Categories
- Flux material
- Alumina material
- Silica material
The first three make up the base glaze. Then any others can go into: - Additives, which includes colourants, opacifiers, suspenders etc.
It is important to understand that the category is determined not necessarily by the main oxide ingredient, but by why we are using it. For example, feldspar contains more of silica than flux or alumina, but we call it a flux material, not a silica material or an alumina material. This is because we add feldspar to a glaze for the flux content, not as a source of silica or alumina.
So we can decide the category by asking the question: "Why am I adding this material to the glaze?"
- If it is to increase the fluxes, it is a flux material, category 1 (see above).
- If it is to increase alumina, it's an alumina material, category 2.
- If it is for the purpose of increasing silica, it is a silica material, category 3.
- If it is to provide a colourant, or opacifier etc., it is an additive, category 4... and so on.
Some materials are borderline cases, and here you have to decide.
