Carolyn DiPasquale on sat 17 may 97
Have recently tried Red/Pink Purple/Mauve ^6 glaze (formula below) on white
stoneware and porcelain. Lighter mauve/pink on stoneware(Fairey's 97) and
darker cranberry on porcelain at the same temp.
In my experience, glazes are often more effective on porcelain than on
stoneware (white stoneware) and I would like to know why. Does the
stoneware absorb more of a critical ingredient from the glaze (maybe calcium
or tin in this case) or, could one of the stoneware ingredients be reacting
with the oxide, limiting its effectiveness as a colorant?
To achieve the darker cranberry on stoneware, can I compensate by adding
more chrome or more "something?" If I added more chrome, would I add more
tin also, keeping the ratio the same?
I guess I am further puzzled because something like Amaco "Glossy Burgundy"
which I have used in small amounts works equally as well on stoneware as on
porcelain. The Mason stains also seem to work equally well. Are our
chrome/tin formulations less stable than the commercial?
Red/Pink Purple/Mauve ^6
21 Gertsley borate
16 Neph Sy
11 Kaolin
20 Whiting
32 Silica
5 Tin
0.15 Chrome
Thank you! Carolyn
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