Tilted toward the sun, this test tile throws shifting reflections across gold, orange, pink, violet, cyan and pale blue, over vertical drips that run down the surface. The back continues those drip formations in mostly turquoise tones. Best of all, the background stays colorful even before any light activates it, where earlier tests by the maker read as murky and ambiguous until lit. As one entry in a series of glaze tests, it looks like a step forward.
The firing setup is a big part of the story. An old barrel, already cut and fitted with handles when it was handed over, was relined with kaowool twice, giving two inches of insulation. A thermocouple sits in an old kiln sitter tube, a propane torch supplies the heat, and the four openings in the lid stay unplugged so the kiln drafts as a simple updraft. Once temperature is reached, fire starter goes in as the combustible while the kiln cools. Most recent tests come straight from, or build on, recipes in Greg Daly's book Lustre.
The chemistry doing the work stands out too. Silver in the glaze volatilizes during firing, a clear liner glaze inside the test cups comes out slightly iridescent, and nearby pieces picked up moly crystals in the kiln. Propane alone only ever produced iridescent edges, and alcohol-soaked q tips helped only marginally, so the jump to fire starter changed the reduction results dramatically.
Two things stay open. Clay bodies come out grey where they take the most smoke, without warm woodfire tones, and it is unknown whether these results will repeat reliably. The maker fires glazes to cone 6 in an electric kiln and has not pushed the barrel that far, having only taken it to around 850C.