Building a Glaze Pantry: Essential Materials for Every Potter

Much like cooking, there are staples for any great glaze pantry. Having a stockpile of materials on hand opens your options to hundreds of recipes that you will be able to mix in minutes . Whether you are mixing glazes from scratch or adding materials to a commercial glaze recipe, a well-stocked glaze pantry is essential.

Firing Temperature Ranges

It is important to start your glaze pantry with a good foundation of commonly used glaze ingredients. There are specific lists for each range of firing temperatures: low fire which is cone 08 to 02, mid fire which is cone 4 to 6, and high fire which is cone 8 to 10 . Many ingredients are shared between the ranges, but some, like frits, you will use in a higher percentage at lower temperature ranges. Others, like stains, need to be tested at mid- and high-fire temperatures before stocking up on them as potential colorants .

Shopping List for Your Glaze Pantry

Use this shopping list to help you get started at your local clay supplier. The list includes the essential materials you will want to start a glaze pantry. Those that are less needed but occasionally called for in recipes are noted as occasional or rare .

For Test Mixing:

If you are mixing test batches, start with 5 to 10 pounds of the basics such as feldspars, frits, kaolin, and silica. Get quarter-pound bags of colorants, opacifiers, and stains. Buy maybe 1 to 2 pounds of rare ingredients. Planning ahead and buying in bulk may save you money in the long run .

For Large Batching:

If you are mixing larger batches, such as 5-gallon buckets, start with 50-pound bags of the basics. Get 5 pounds of Zircopax. Buy half to 1 pound of oxides and common stains. Purchase 5 to 10 pounds of less common ingredients. Use a spreadsheet or glaze calculation software to keep track of ingredients, amounts, and pricing .

Basic Glaze Materials

Feldspars are the backbone of most glazes. They provide the glass-forming components that melt to form a glossy surface. Common feldspars include Custer, G-200, and Nepheline Syenite.

Frits are pre-melted glass that has been ground to a powder. They are essential for low-fire glazes because they melt at lower temperatures. Common frits include Ferro Frit 3124, 3134, and 3195.

Silica or flint provides the glassy matrix in glazes. It is essential for forming a hard, durable surface. Silica also raises the melting temperature of a glaze.

Kaolin or China clay is used to suspend glaze ingredients and add workability. It also contributes to the glassy matrix. EPK kaolin is the most commonly used.

Whiting or calcium carbonate provides calcium oxide, which is a flux that helps glazes melt. It is also used to create matte surfaces.

Stains and Colorants

Zircopax is an opacifier that makes glazes white or opaque. It is essential for many bright glaze colors.

Metal oxides produce specific colors. Copper oxide or carbonate produces greens and blues. Iron oxide produces browns, reds, and blacks. Cobalt oxide produces deep blues. Chrome oxide produces greens. Manganese dioxide produces purples and browns.

Commercial stains are pre-mixed colorants that give consistent, predictable results. They are available in dozens of colors.

Storing Your Materials

Materials should be stored in plastic bags or plastic-lidded containers. Paper bags can dry rot and the adhesive can dry out, allowing chemicals to spill and cost you money. Paper bags also allow moisture to get through the bag and chemicals can harden . Always label your bags and containers with the chemical name. It is a good idea to keep a record of where and when you purchased your materials in case you have questions later .

Essential Glaze Pantry Equipment

Scales are critical to proper mixing and not wasting ingredients. Buy two scales: one that is accurate to the gram and has high-capacity capabilities of at least 5000 grams and one for small test batches that is accurate to one-hundredth of a gram so that you can measure expensive colorants accurately .

Sieves ensure uniform and consistent glazes. A 40-mesh sieve is good for raku glazes and for granular ingredients. A 60-mesh sieve is for the first run of a glaze. An 80-mesh sieve is for glazes with fine colorants such as oxides and stains. For high-firing glazes such as celadons, a 100-mesh sieve may be needed .

Safety Equipment is non-negotiable. Always have a dust mask or a respirator, gloves, and wet clean-up equipment such as a sponge and a mop. Work in a well-ventilated area, whether that is near an open door or window or by a vented space .

Miscellaneous equipment includes scoops, buckets with lids, whisks or stirring paddles, and labeling tools. Material Safety Data Sheets are also helpful to have .

Additional Equipment

Once you have the foundations of your glaze lab set up, you may want to consider adding a few additional items. A drill mixer for mixing large batches of glaze in 5-gallon buckets is very helpful. An immersion blender is useful for mixing small test batches. A rack or rolling cart keeps bulk ingredients off the floor. A sturdy table for mixing is essential. Glaze software can help with recipe calculations and inventory management. A vent equipped with a dust filter is important for safety .

At Black Stone Ceramics, we stock a full range of glaze materials, stains, and essential equipment. Our team can help you select the right materials for your firing temperature and glaze goals.