96 - Another Blue Enamel
As an example, take 4lbs of enamel base material. With this, thoroughly mix 2 oz of prepared zaffer, but first mix in 2 pwt of thrice cooked copper, made with the flakes from the kettle· smiths, as was described in its place [chapter 28]. Thoroughly blend these two [unified] powders with above enamel base material.
Once they are mixed, throw them into a crucible glazed with white glass, and put them in the glass fumace. When it is fused and well clarified, dump it into water, and repeat. Put it into the furnace and leave it to cook and clarify thoroughly. Finally, remove it from the furnace. The result will be a most sightly blue enamel for goldsmiths.