How can I tell if glass is real Depression glass?

Genuine Depression glass was made by machine in large molds, so it has a few telltale traits. Look for tiny bubbles in the glass, faint mold seams, and slight unevenness in the pattern. Many pieces have a ground or rough ring on the bottom where they sat in production. The glass is usually thin and fairly light compared to heavy modern pressed glass.

Pattern and color matter most. Depression glass was made in specific patterns with names like Cherry Blossom, Mayfair, American Sweetheart and Royal Lace, and each pattern came in a known set of colors and shapes. If your piece does not match any documented pattern, or comes in a color that pattern was never made in, it may be later glass or a reproduction. Some Depression glass glows under a blacklight because of uranium content, but plenty of genuine pieces do not, so that test alone proves nothing.

The surest route is to compare your piece against photos in a pattern reference guide, paying attention to the details of the design, the base and the weight. A dealer who specializes in American glass can usually confirm it quickly in person.