I finally got around to doing this. The borosilicate 4 oz pouring cups work well for 3 & 4 color open pour molds. Wanting to keep the cups warm to extend open time, I molded this hi-heat sandy clay in a griddle with lid. Keeping the molds warm on the flat griddle really helps the colors blend slightly “fuzzy” instead of sharp defined lines. Just getting started; will update after more use.