I have been using Schauer #43 Crkis enamel on fine silver
(1000/1000) for many years now, and it used to be one of my
favourite colours. Recently I have regularly experienced, however,
that after firing it 3 to 4 times it turns dull. I have looked
through all available written resources, but to no avail. Solder
flux cannot play a role, as the phenomenon also occurs if the silver
has been milled. Also I alway use distilled water and pay particular
care to prevent polluting the enamel. Most recently I tested by
firing 8 times on 1000/10000 silver with excellent results, then
used the powder from the same batch in a work piece and it turned
dull again. As I like to use colour shades I often use #43 with other
Schauer enamels, usually # 61, 157, 174, 140. I have wondered
whether this underlies the problem but have almost certainly
excluded that; but then, with enamels one never knows. I would be
very much obliged ineed if anyone could help me resolve this
problem.