Test tiles are out of the kiln. The one made from Alexis’ frit 3124 is fine, and the one made from the studio’s whatever-is-in-the-frit-3124-tub is milky and pinholey where thick. (But the application was very, very thin, which makes a difference, and someone actually had the balls to say, “But it turned out nothing like your other firings”, which is slightly angry-making, but ANYWAY. If it’d been applied thickly, you can clearly see the result would have been the same as in the catastrophe firings.)
So. I know for sure the problem is where I thought it was all along. And the bag of new frit I’ve ordered will not have been ordered in vain. And as soon as it effin’ gets here I can glaze the small mountain of bisqued Robots I have accumulating on my shelves.