Reds are the most persnickety glazes there are! Too thin in some reds
and they turn out white....Overfire and they turn whtie or black. You
have to do EXACTLY what they tell you to do on the label. You know how
you can get away with overfiring many low fires, pushing them to cone 04
or 05, and they still look about the same. Not reds. In fact, I
usually tell my kids to put on 4 coats of red. Nothing is sadder than a
bad red when you open the kiln!