January and February are usually somewhat slow months for orders/commissions so I use the time to try out new ideas and do a fair amount of testing. In case it isn't crystal clear, I tend to do a fair amount of testing based on iron and copper glazes. Honestly, the potential for both is nearly infinite and the result are generally exactly what I am after. I recently tried altering an old soda based clear glaze I have by adding copper to it and didn't add a pinch of iron to temper the color. The initial results were quite good, giving me an Oribe style glaze, very similiar to the old lepidolite Oribe. I was rather pleased and moved onto the next phase of testing.
I threw a group of yunomi and white slipped them, using hakeme and kushime style decoration. Once bisque, I glazed up four of the yunomi and ended up firing them and various parts of the kiln. I guess I had forgotten a crucial part of this narrative, the original tests were not on white slip, but rather straight on plain stoneware pods and rings. What came out of the kiln was a GREEN made brighter and greener because of the white slip. A simple overlooked issue, though now I know what to expect. I am thinking I will reduce the copper content and add .5% red iron to lessen the impact. It is not a bad green, but in person, it sure is green.
"What are facts but compromises? A fact merely marks the point where we have agreed to let investigation cease." Bliss Carman (1861-1929)