83 - A Celestial Colour
Take 2 oz of rock crystal, ground impalpably as before, and add 5 oz of ordinary minium. In all, there will be 7 oz of material. Blend it together thoroughly, and to this add a proportion of 3 grains per ounce of prepared and ground zaffer. Therefore, in all give 21 grains of zaffer to the 7 oz, and blend them thoroughly, as was said for other pastes above. Put it into a crucible, with the aforementioned observations. Consign it to a pottery furnace, or purpose-built kiln. You will have a most graceful celestial color.