Thursday, 14 February 2013

"Bronze" glaze effects

Recently I've been making some forms which were partially influenced by ancient artefacts such as burial urns. I thought a bronze-like finish would be ideal for some of them, but I'd never come across any suitable recipes, apart from manganese-based glazes, which I'm reluctant to use because of potential health hazards. By a complete coincidence, I fired a couple of pots yesterday in saggars, and lo and behold, the glazes came out heavily reduced and looking rather like bronze! Well, various shades of dark green, grey and purple, which reminded me of the patina one sees on some ancient bronze objects.

Tea or wine cup, 3.25 inches tall
Sake cup, approx. 3 inches tall

I also fired some pieces with the matt ochre-ash glaze in oxidation, and these came out quite strongly yellow in colour. This glaze is very much affected by depth of application. When thicker it can turn quite blue-green from the ash content, and where thinner it can be red-brown to black. This time the thickness was moderate and even, so the colour is a fairly solid yellow with a few dark brown areas where it has broken on ridges. The yellow does have a slight green tinge to it, which I think is because the ash in this glaze batch contains alot of pine. I'm interested in developing a glaze similar to Japanese Ki-Seto and this matt ochre recipe (which I have adapted slightly from John Jelf's original formula) comes reasonably close, especially in the way it develops red-brown "scorch" marks in places.

Vase with matt ochre ash glaze, 4 inches tall


  1. On the first pot I notice some gold spots at the bottom, what are those from, I like them? Any glaze that breaks in reduction I love the look of.

  2. Thank you, Linda, the gold spots are actually finger marks..and it's the iron in the clay body which turned gold under heavy reduction.