Fired Silver Paint: Five Parts Silver to One Part Lead Borate, Ground in Oil (NBS Circular 468, 1947)

A silver paint for ceramic and glass that is fired on: metallic silver for the metal, lead borate glass as the flux that melts and holds it, and oil to make it brushable. Use as little flux as will hold the silver; more flux conducts worse. Source: Brunetti and Curtis, Printed Circuit Techniques, NBS Circular 468 (1947): five parts metallic silver or silver oxide to one part binder such as lead borate, ground in a paint mill with vegetable oil, thinned with a little acetone. This is the metallic silver version. Not given: the firing heat, which depends on the flux and the plate. Ours: linseed oil, a glass muller, and the 60 g batch. Lead borate is poisonous: gloves, no dust. Picture drawn by Youblob.