Milk glass has been around since the 17th century and grew more common as the years went on, hitting a boom in the 1950's. It can be difficult to identify true milk glass with all the reproduction glass on the market, but with a careful eye and a knowledge of milk glass you can learn to spot it.
Get familiar with the various manufacturers of milk glass and their unique styles.
Start shopping. When shopping for milk glass pay careful attention to markings on the glass. These may be on the bottom or side and sometimes have a date. Some common branding to look for are Fenton, Imperial, Fostoria and Westmoreland. On very old milk glass, usually pre-1900's, there will be no markings; the telltale sign of such an old piece is to look at the edges, it will be semi transparent.
Learn to determine the importance of colors and patterns on milk glass and how it affects its value and authenticity before making a purchase. For instance the hobnail pattern crafted by the brand Fenton, has very distinguishing ruffles and buttons in the glass. Westmoreland, another milk glass brand, typically use rabbits or fruit as a pattern. Counterfeit milk glass generally has no pattern or marking.
Take your milk glass to an appraiser to get it dated and priced.
Learning to identify milk glass is a skill that takes a lot of research and commitment, if you make a mistake and buy a reproduction don't beat yourself up over it.
Be wary of chips, replaced parts and damage before purchasing a piece of milk glass.