Ravenscroft Glass:

George Ravenscroft made flint glass and used lead glass to produce a fine crystal glass. Ravenscroft was know as a master of "wrythen" and "nipp'd diamond waies" methods of tooled decoration. Ravenscroft had a factory at Henley on Thames, England; and marked some of his fine wares with a raven's head pressed into a prunt of glass.