Milk glass is identifiable by its milky white color and its patterns and shapes. Collectible milk glass became popular in America in the mid-1800s, and it reached its highest popularity at the turn of the century.
Popular shapes of milk glass included dolphins and later, birds. Common patterns included "block and fan" and "buttons and arches," as well as ribbed grapes and drapery patterns reflecting major events of the day. Glass from the 1800s is a duller, more opaque white than later examples, although some pieces may be translucent at the edges.
Newer pieces have a rich, milky white color. Common patterns include hobnail and paneled and beaded grapes. The most commonly collected milk glass originated in mid-20th century, and the pieces often have the manufacturers' stamps on the bottoms. Major manufacturers include Fenton and Westmoreland.