Swellegent, that is! I mentioned the product in a post about the workshop I took with Christi Friesen last month. The Swellegent products are finely-ground metals suspended in a binder. They thin and clean up with water, which make them extremely easy to use, but because they are metal they can be oxidized or given a patina.
I thought they would make nice accepts on giftware, as well as being useful for things like tack hardware and shoes on those ceramic pieces that have them. I ordered the Copper version to test, thinking that it might compliment the crackle glazes on these Clinky Classic Challenge Awards. I added Copper on the cups being held by the horses right over the existing glaze, and then used the patina to darken it. As you can see, it matches the antique copper on the findings perfectly.
The slick surface did make it a little more difficult to handle, and I was glad that I was only adding the metal to a small area. I decided to try another experiment with one of my own Inspire tiles, this time leaving the bare bisque where the metal coating needed to go.