Shino tests

I'm teaching a glazing class at Claymakers, and we're focusing on American carbon-trap shino glazes fired to cone 6-7 in Claymakers' gas kiln. Carbon trapping happens thanks to soda ash dissolved in the glazes. As a glazed pot dries, soda migrates to the surface and crystallizes. These crystals can bind with soot that's produced by the reduction (low oxygen) atmosphere in the kiln, yielding smoky grays and blacks, on top of the whites and oranges typical of shinos. Wax resist swooshed onto the drying glaze prevents crystals from forming where the wax is, but can also encourage crystal formation along the edges of the waxed areas.

Here are some of my pots from our first firing; we'll fire again next week.

Malcolm Davis Shino with 6% Redart. The swoosh and dots are from wax resist.
The glaze was thick, and the pot was in a heavily reduced spot in the kiln.

Three salt rocks: Dresang Shino, Malcolm's Shino w/Redart and Carbon Trap Shino.
The swooshes, dots, and squiggles are all thanks to wax resist.

Cadogan teapot (a lidless teapot that fills from underneath, like a salt rock
with a spout); Malcolm's Shino w/Redart, wax resist. The pot was next to the jar in
the kiln, so well reduced, but the glaze was thinner--thus not as intensely black.