In answer to your question about red over white clay for scraffito or
I use low fire clay in my classes. Made two examples using a red clay over
a white clay, both the same firing temperature. Made the white slabs, used
thick red slip over the top, let set up to a slightly drier state. Then
used fine loop tool to incise design. Assembled. Touched up incised lines.
No problem. Works great. Linda K.