The art of glass shewing how to make all sorts of glass, crystal and enamel : likewise the making of pearls, precious stones, china and looking-glasses : to which is added, the method of painting on glass and enameling : also how to extract the colours from minerals, metals, herbs and flowers ... : illustrated with proper sculptures / written originally in French, by Mr. H. Blancourt, and now first translated into English ; with an appendix, containing exact instructions for making glass-eyes of all colours.

CHAP. CLXXXVII. To make White for Painting on Enamel.

THE best Workmen, for the most part, use the White Enamel ground, which they can ma∣nage with address enough to heighten and illustrate their Lights, which is necessary to be done to all their Colours, as in Miniature: But as it is difficult to pre∣serve the Ground justly for improving those other Colours, and ordering the Compositions (all one as in Carnation) you must take of our Crystal ground prepared with Tin and Lead purged and refined as in Chap. 158. or rather of our Milk-colour Enamel in Chap. 159. which is the fairest can be made; cleanse it with Aqua fortis, wash, dry, and grind it after∣wards with Oyl of Spike.

Or you may prepare another White Ground with∣out Lead, thus: Take very pure Tin calcined, as in the Chapter aforesaid, and let it vitrifie in a Glass-house Pot, with eight times as much Crystal Frit, as we have directed the Preparation in Chap. 6, pulverize

these very fine, and proceed precisely according to Prescription for Purification, &c. in Chap. 158.