Explorations into Cone 6 Crackle Slip Ceramic Surfaces By John Britt Assisted by Alexandra Barao In this PDF I explore crackle slip and the best ways to achieve this surface. Although it is primarily cone 6, you can use it at cone 10 and I do have 2 low-fire slips recipes. I have been using this Crackle slip recipe for over 30 years and put it in my first book, “The Complete Guide to High-fire Glazes” published by Lark Books in 2004. Although I originally employed this technique in soda and wood firings, I wanted to adapt it for use at cone 6 electric firings to achieve a similar look. While I was working on my latest PDF entitled, “Sculptural Ceramic Surfaces,” I rediscovered my love of this surface. I used it a lot frequently on sculptures I made to mimic aged and excavated bones and skulls, mostly at cone 6 and low-fire. In the past I applied it haphazardly; if applied too thick, it would crack off, while too thin a layer wouldn’t produce a crackle effect. For the skulls and bones, a rough and ragged appearance added to the natural look. Often, I would reapply and refire multiple times until I was satisfied with the surface. However, for more functional work, I felt the need for better control.
