A Royal Scot Crystal whiskey tumbler collection. A Royal Scot Crystal whiskey tumbler with Edinburgh Castle on the side. A Royal Scot Crystal decanter with two whiskey tumblers. In 1676, it was discovered by British glassmakers that the addition of lead oxide to their raw materials gave the resulting glass a much greater brilliance and sparkle. This new glass became known as lead crystal and very quickly became the perfect medium for glass cutters and engravers. Over the past 300 years, their skills , proudly passed from generation to generation, have given lead crystal its world famous reputation. In the Royal Scot Crystal collection you will find a tantalizing range of crystal items all hand cut, demonstrating the outstanding skills of the master craftsmen.