Milk glass is an opaque milk white or colored glass that can be blown or pressed into a wide variety of shapes, it has been produced since the 16th century.

Made into decorative dinnerware,lamps,vases and costume jewelry milk glass was highly popular during the fin de siècle. Pieces made for the wealthy of the Gilded Age are known for their delicacy and beauty in color and design, while Depression glass pieces of the 1930s and 1940s are less so.

Milk glass is often used for architectural decoration when one of the underlying purposes is the display of graphic information. The original milk glass marquee of the Chicago Theatre has been donated to the Smithsonian Institution. Famous use of milk glass is for the four faces of the information booth clock at Grand Central Terminal in New York City.