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semi-opaque glaze cone5/6 - addendum

updated mon 1 oct 01


Diane Winters on sun 30 sep 01

Further to the info and glaze I posted (what's the email equivalent of
"measure twice, cut once"? "think twice, post once"?):

Just to clarify what I said about the "breaking" of Toshiko Green - that
occurs when you use the formula as originally written; the breaking does not
occur when you eliminate the copper from the formula or use other colorants.
It is also pretty well eliminated in the copper green version, as I said, by
cutting the zinc way down.

As the basic Toshiko glaze has a great deal of calcium as well as the fairly
high zinc, the oxides produce slightly different color effects than in a
different type of glaze. For example, I have to use 4% red iron to get a
medium ocher, and its a dusty ocher at that, so I enrich it with at least
1.5% Mason Stain 6433. Less red iron, more 6433 could give a dark yellow.
(I cut the zinc in this varient down to about 5%).
To get a moss green I'd use a combo of copper (1 - 2%), MS 6433 (8 - 10%),
and a tad red iron (maybe 1.5 - 2%), again with zinc content about halved.

Diane Winters
in Oakland/Berkeley, where after a long, cool summer, we may even get up to
82 F today. When your body's adjusted to highs in the mid 60's, believe me
that can feel like a heat wave.