Notes on Clay

Notes on Clay

October 12, 2022

In recent years I’ve worked mostly with clay bodies formulated to reach a semivitreous state at a very high temperature, and containing a mix of fireclay and ball clay among other materials. These clay bodies are commonly referred to as “stoneware” bodies, of which there are a great variety, and the temperature range is commonly described as “high-fire.”  My longstanding favorites are Soldate 30 and Soldate 60, formulated by the late artist and California State University Los Angeles professor Joe Soldate, and manufactured by both Laguna Clay Company and Aardvark Clay and Supplies. The Soldate clay bodies actually have a fairly wide firing range, but I take them to the higher end of that range, usually firing to slightly in excess of a cone-10 heatwork measurement, and peaking at around 2350 to 2400 degrees Fahrenheit depending on firing time.

I generate a lot of waste as I build, and so I reclaim and remix clay. This affords me an opportunity to keep on hand clay of all the same general type but of many consistencies, from thin and thick slips to putties, clay that ranges from soft and squishy to firm (like what we tend to imagine when someone says “clay”), to stuff that is still moist but so stiff you can’t put a dent in it. I use all of them as they suit my needs for construction.

Over the last couple of years, I’ve moved to mostly working with clay bodies of my own formulation that I mix from raw materials in the studio. This has to do with achieving certain colors, textures, and working and firing properties. I’ve also moved toward formulating clay bodies comprised mostly of raw materials from California.

Though I’ve been devoted to working at the higher end of the heatwork/temperature spectrum for studio ceramics, I am now experimenting at the other end of the spectrum, testing clay body formulations that might achieve semivitreous states at temperatures that more typically yield very porous “earthenware” fired products.