I don't know why I never just make test tiles, but I don't. Maybe someday when I have my own kiln... In the meantime, I just experiment on my own work. Here, I'm trying to devise a relatively authentic Oribe green glaze. I started with a tried and true clear glaze that fits our studio's stoneware body, Baccerra clear, and added 3, 5, 7, 9 and 12% copper carbonate to 100g test batches. I'm most satisfied with the 5%, however I suspect that I either mixed the 7% batch a little too thick, or dipped the test pot for a little too long, as it seems to be as dark (or darker) than the 9% batch.