Who knew that making test tiles and mixing line tests would take sooooooo long? Not to mention waiting for them to be fired. The pre-test tiles showed that 6% was the best test colour intensity for all but white (more needed) and black (less needed). For these tests I concentrated line tests for red/yellow, blue/yellow, red/blue. All were Wendy’s stains from ATC Colours, which performed the best in the pre-test, with the possible exception of yellow. I thought I was using Dave’s engobe recipe for both sets of tests, but it turned out to be an amended recipe with more Borax frit 50:25:25. The round tiles below are pre-test tiles, pure stains.
Unfortunately, these tiles were put in a stoneware firing, so I can’t compare the yellows, as I’d intended. Fortunately, however, it means I now know the stains are fine at stoneware temperatures. And it’s shown that primary colours can be mixed to produce secondary colours – which was the purpose of the tests.
And I know I want a more vitreous finish than the engobe. Dave suggests trying his dolomite glaze, and I’ve found a couple of satin glaze recipes to test. I need to test these with pure stains, then redo the above tests, adding more variation between green/yellow, orange/yellow spectrum. Also, the purple is plummy. Perhaps a more cyan primary might give a better colour?
I’ve made a gazillion test tiles – and lost a week with a bad back as consequence. I MUST sort out my work station to more ergonomic.
I used up the leftover engobes to layer over my old biscuit fired pieces from the first projects:
The higher temperature made them almost glossy, and I rather liked the layered effect.