Lili Krakowski on fri 9 nov 07
In "Pioneer Pottery" Cardew tell us that "cobalt silicate is an unpleasant,
'hot' blue ,tending to violet. The aluminate is a cold, startling and
rather 'artificial' colour, but is free from any taint of violet." He goes
on to say that cobalt is better used "extended" and gives the following
recipe which I always use with happy results.
Cobalt carbonate 20
white tin oxide 20
Black manganese oxide 10
Talc schist* 10
Plastic red clay 15
China Clay 20
Red Iron Oxide 5
I know that schists are a rock formation, but do not know if one needs to be
sure to use that. I use plain talc, and my red clay is RedArt. I use any
china clay/kaolin handy. As with all homemade "stains" I mix with lots of
water, let stand a few days, sieve, adding water if needed, sieve again and
allow to dry out.
A warning however! I once was lied to by A Prominent Clay
Manufacturer--now gone, thank goodness. I was told that a c.6 white clay
body contained no talc, no magnesium! I therefore, foolishly--a youth!--did
not test...and made a bunch of lovely--even if I say so myself--pots for a(n
invitational) show, all of which turned out to have purple decoration! So
much for the cool Delft look.
So if cobalt blues disappoint consider the body.....
Life can be cruel....
Lili Krakowski
Be of good courage
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