Tried out a polymer clay push mold. Almost, but no cigar. Didn’t release well. Mold split at corners.
So I tried a bit of reinforcement and re-baking to see if the mold could be salvaged. Meanwhile, started my second attempt at a latex rubber mold. So far so good. Three layers of rubber in, at least that many more to go before I can make the mother mold to go with it.
The re-baked press mold worked out just fine. De-molding the tile involves deforming it a bit, but nothing that couldn’t be worked out. The tile baked fine. Even better, it really took the paint. I think the talcum powder used as a mold release might double as a built-in primer if things I’ve read all tie together that way.
Here’s the new polymer clay tile, all painted up to the best of my n00b ability.