A ceramics experiment: We have a glaze in the studio that's known as a carbon trap type glaze because it has the ability to trap soot from the firing within itself, leaving interesting black patterns and blemishes on the finished piece (this is not the same a raku).

I don't know why we have that glaze, because the way they fire the kin, it never gets sooty. I manually added soot to these pieces with a candle to see if it gets trapped in the glaze and survives the firing.

It may not. If the kiln is too oxidizing at any point, the soot will burn off. We'll see!