Ingredient Amount
Talc 352.90
EPK Kaolin 176.50
OM 4 Ball Clay 470.60
Add Amount
Zircopax 117.60
Water 8.00


I mix these terra sigillata recipes in 1000 gram batches, which require 8 cups of water. To make the mixing easier, I use wide mouth gallon jugs, and prefer glass so it is easier to see whether the layers have separated.

Making Terra Sigillatas

Mix deflocculent (I use sodium hexametaphosphate, a fabric water softener from the Dharma Trading Company) in warm water, preferably in a blender, pour into a container with correct quantity of water and add dry materials. After sieving, ball mill the terra sigillata 6–8 hours to increase the amount produced in a measured batch and reduce waste. After ball milling, let the terra sigillata settle for a week or more in a clear container, ladle off the clear water layer on top, then pour off the middle layer of terra sigillata. A layer of larger clay particles will have settled on the bottom of the container.

This recipe was shared by Alan Willoughby in the April 2019 issue of Ceramics Monthly.