Instructions
Purchase a depression glass reference book, a tool that any serious collector should have to help them recognize authentic glassware. The best reference guides for depression glass are "The Collector's Encyclopedia of Depression Glass" by Gene Florence and "Colored Glassware of the Depression Era" by Hazel Marie Weatherman.
Familiarize yourself with the most famous depression glass makers, the colors they used and their particular glass designs. Search various manufacturers and photos online, and with a little investigation you will easily begin to recognize the repetitious patterns used to make depression glass. Some of the most well known depression glass manufacturers include Cambridge, Fostoria, Hazel-Atlas, Heisey, Hocking, Morgantown, Paden City, Tiffin, U.S. Glass and Westmoreland.
Identify depression glass by examining the glass for little bubbles, a characteristic that demonstrates its mass production. Depression glass was made to be affordable, not necessarily for quality. While the patterns and colors are beautiful, depression glass is famous for bubbles and other imperfections.
Check the glass for marks left by the mold. These machine-made glass pieces are not perfectly finished, therefore all depression glass with have a very distinct line running through the middle that has been left by the mold. If you cannot find mold marks, you are not looking at depression glass. Most avid depression glass collectors know and accept the fact the flaws come with the territory.