The most popular color of opaque glass is white, or "milk glass," a term introduced in the 20th century.   However, Opaque glass has been around since 16th century Egypt, and probably goes even further back to the Chinese in the 2nd century.  "Opaque" by definition means "not transparent or translucent; impenetrable to light; not allowing light to pass through."  Check out our large selection of white milk glass!