Various Glazy Materials

What is a Material?

Strictly speaking, a Glazy Material is just a chemical analysis that represents a real-world material.

The accuracy of the analysis may vary. The actual composition of each bag of your material may differ more or less from the analysis.

Theoretical Materials

All material analyses are to some extent theoretical in that they approximate actual real-world materials. The actual materials we use in the studio come from various natural sources and contain impurities and inconsistencies. For example, there are many types of Potash Feldspar, and each type has a different analysis. Even within types of Potash Feldspar, there may be different analyses for different batches of material at different times.

Imagine you are at a grocery store but didn't know what to cook. So you and find the following recipe via an app on your phone:

Roasted Delight


  • 1 carrot
  • 1 onion
  • 1 pound of meat
  • 1 teaspoon of salt
  • 1 teaspoon of pepper

What does "1 pound of meat" mean? It could be steak, chicken, or fish, and the final dish would be much different with each type. You see in the recipe reviews that people used fish, but they didn't mention what type of fish. Freshwater, saltwater?

Just as with our fictional "Roasted Delight" recipe, some older glaze recipes just list "Feldspar" (meat) or "Potash Feldspar" (fish).

A sample of analyses for Custer Feldspar, a type of Potash Feldspar:

Custer FeldsparFeldsparPotash Feldspar68.5017.00 0.3010.003.00 0.100.30
Custer Feldspar (1989)FeldsparPotash Feldspar68.6417.39 0.3010.363.02  0.30
Custer Feldspar (2000-2012 Ron Roy)FeldsparPotash Feldspar72.4015.
Custer Feldspar (pre-2000)FeldsparPotash Feldspar68.7017.250.050.1810.063.040.310.120.66

When working with actual materials in the studio, it's best to use the most accurate analysis you can find for each material.

Material Metadata


Materials can be set as a subtype of one of the following values:

Alumina, Ash, Clay, Colorant, Miscellaneous, Feldspar, Flux, Frit, Opacifier, Silica

This list of subtypes was inherited from imported recipe data and are still used because no one has yet suggested a better list. The subtype is simply an organizational tool used to group materials together.

Parent Material

While not a required field, Parent Material is quite important for the functions of Glazy. Namely, this field is used to determine whether or not materials and the recipes that use these materials, are similar.

As an example, let's look at the classic Leach 4321:

  • 40 Potash Feldspar
  • 30 Silica
  • 20 Whiting
  • 10 Kaolin

Now imagine you wish to make a batch of this recipe. You look everywhere in your studio for materials called "Potash Feldspar" and "Kaolin" but cannot find them. However, you do find "Custer Feldspar" and "EPK", and you realize that these materials are types of Potash Feldspar and Kaolin, respectively. Your final recipe batch of Leach 4321 is:

  • 40 Custer Feldspar
  • 30 Silica
  • 20 Whiting
  • 10 EPK

While technically both of the above recipes are "Leach 4321", they differ in both materials used as well as final chemical analysis. However, when comparing glaze recipes we often want to overlook slight differences in chemistry between similar materials (in this case, types of Potash Feldspar and Kaolin). That is not to say that these differences are not significant, and in fact some material substitutions may give quite different results.

In Glazy, materials are organized into a tree. In other words, materials can have parents and children. In the case above using Leach 4321, "Custer Feldspar" is the child of "Potash Feldspar". Similarly, "EPK" is a child of "Kaolin". This is because there are many types of "Potash Feldspar" and "Kaolin", "Custer Feldspar" and "EPK" being just a couple of them.

When Glazy attempts to find similar base recipes, it does so using the immediate parent materials. In the above batch of Leach 4321:

  • 40 Custer Feldspar (Parent: Potash Feldspar)
  • 30 Silica (No Parent)
  • 20 Whiting (No Parent)
  • 10 EPK (Parent: Kaolin)

In this case, the recipe used for comparison is:

  • 40 Potash Feldspar
  • 30 Silica
  • 20 Whiting
  • 10 Kaolin

Obviously, this is the same recipe as our original Leach 4321. So Glazy recognizes these two recipes as equivalent.

When adding new materials to Glazy, it is advisable to specify a Parent Material if possible.

For example most Potassium Feldspars, the parent should be "Potash Feldspar" (owned by the Glazy Admin). If adding EPK, SSP, or Helmar Kaolin, the parent should be "Kaolin".

Parent & Siblings

In the Material page you will see a Parent Material listed along with any Sibling Materials. Sibling Materials are simply materials that have the same Parent as the current Material. In the case below, Custer Feldspar's Parent is Potash Feldspar, and its Siblings include other Potash Feldspars like Mahavir Potash Feldspar.

Parent & Sibling Materials


There are currently only three status levels:

  • Testing: A material that is not actively being used in the studio.
  • Production: A material that is actively used in the studio.
  • Discontinued: A material that is no longer available, for example the mine has closed down.

Only materials with a status of Production are displayed in the default Glazy search page.


Often it can be useful to associate a material with a Country. While theoretical materials like "Feldspar" don't have a location, others like "Mahavir Feldspar" is tied to a specific mine. Some ceramicists prefer to use locally-sourced materials, and the Country field can help guide them.

Create a Material

You can easily add your own materials to Glazy:

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