Rummer with Raven Seal - Technique

Listen as glass artist William Gudenrath describes the technique used to make this Ravenscroft goblet. In March 1674, the English glassmaker George Ravenscroft applied for a patent to make colorless lead glass. Unfortunately, this glass was prone to crizzling, a chemical instability that results in an attack by atmospheric moisture, producing a network of cracks in the surface. Ravenscroft revised his formula, adding more and more lead glass. This new lead formula was used to make this rare Ravenscroft goblet. The goblet is decorated with mold-blown ribbing that is pinched to form a mesh design on the bowl. This pattern is called "nipt-diamond-waies." One of the prunts at the bottom of the stem is stamped with a raven's head, taken from the Ravenscroft family's coat of arms.