Published Feb 8, 2021
Commercial glazes are awesome and super reliable, but I also like to use glazes that I mix on my own in my work. If you feel the same but don’t know what materials you should purchase to have a well-rounded glaze pantry, today’s post is for you!
In this excerpt from her book Off the Shelf | Outside the Box, Deanna Ranlett shares her advice for stocking up on raw materials, along with a pretty handy materials chart showing how common glaze materials are used at various firing temperatures. - Jennifer Poellot Harnetty, editor.
Much like cooking, there are staples to any great glaze pantry. Having a stockpile of materials on hand opens your options to hundreds of recipes you’ll be able to mix in minutes.
A Good Foundation
It’s 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 (cone 08–02), mid fire (cone 4–6), and high fire (cone 8–10). 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.
There was a time when using commercial glazes, underglazes, and clays was frowned upon in the clay community. It was somehow cheating; the stuff of "Paint Your Own Pottery" shops. But not anymore! In our book, Off the Shelf | Outside the Box, Deanna Ranlett explores the nuances of commercial clays, glazes, underglazes, and more, as well as the variety of results that can be achieved with these products. If you are interested in these versatile, convenient and easy-to use products, this book is the perfect place to get started!
While it’s hard to recommend material quantities without knowing what batch sizes you’ll be mixing, I usually give the following guidelines:
If you’re mixing test batches, start with 5–10 pounds of the basics (feldspars, frits, kaolin, silica), ¼-pound bags of colorants, opacifiers, and stains, and maybe 1–2 pounds of rare ingredients. Planning ahead and buying in bulk may save you money in the long run.
If you’re mixing larger batches (5-gallon buckets), start with 50-pound bags of the basics, 5 pounds of Zircopax, ½–1 pound of oxides and common stains, and 5–10 pounds of less common ingredients. I’d recommend using a spreadsheet or glaze calculation software to keep track of ingredients, amounts, and pricing.
Use this shopping list to help you get started at your local clay supplier. The list includes the essential materials you’ll want to start a glaze pantry and labels them as “common.” Those that are less needed but occasionally called for in recipes are noted as well followed by “occasional” or “rare”.
Note: I have placed an asterisk (*) next to ingredients to buy in bulk if you’ll be mixing multiple batches or large 5-gallon buckets—although most ingredients can be purchased in various small quantities, 50-pound bags can save a significant amount of money. If it’s your first time mixing and you’re only mixing a few tests, a 5-pound bag would suffice.
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; an immersion blender for mixing small test batches; a rack or rolling cart to keep bulk ingredients off the floor; a sturdy table for mixing; glaze software; and a vent equipped with a dust filter. Have fun experimenting and building your glaze pantry!
Deanna Ranlett owns MudFire Clayworks and Gallery (www.mudfire.com). She has been a working ceramic artist for 13 years.