Double Overlay Glass is decorative glass produced by layering two differently coloured gathers of molten glass before cutting or engraving through the outer layer to reveal the contrasting colour beneath. Popular during the nineteenth century, particularly in Bohemian and French glassmaking, double overlay glass allowed craftsmen to create intricate decorative patterns with remarkable depth and brilliance. Antique examples are highly prized for their technical complexity and artistic quality. *Related Terms*\ Bohemian Glass, Cameo Glass, Cut Glass, Overlay Glass, Ruby Glass.