Antique and collectible glassware has had competition for years. This competition is in the form of reproduction glassware made to look like old and collectible pattern glass from the turn of the 20th century, but produced after 1930 or even after 1990. Depression glass and carnival glass reproductions are common, too. Some reproductions come from the United States, many from the molds of the original maker. The Henry Ford Museum, the Smithsonian, the Sandwich Glass Museum and the Metropolitan Museum of Art have approved reproductions of early glass, and these reproductions are marked on the bottom with the initials of the museum. In recent years, most reproduction glass has been imported. You can learn to identify reproduction glass with experience and study in antique glass, but a few shortcuts may make identification easier.
Look closely and feel the surface to detect reproduction glassware. Old glass will have some wear and scratches from use or storage. The bottom should have some dullness where the base touches the table, reports PBS's "Antiques Roadshow." Reproduction carnival glass is shinier. Older carnival glass has a satin, almost velvet, iridescent finish. Old glassware also has flaws--an occasional bubble or shear marks are common. Most imported glass feels greasy, a quality not seen in old American glass. Bubbles in imports, instead of occasional, often appear as seediness, or tiny bubbles throughout the glass. This is a sign of poor-quality reproduction glass.
Check the weight and crispness of the design. Reproduction glassware is often heavier than the original, sometimes thicker on the sides as well as at the base, and sometimes just the base is heavier. Depression glass reproductions are often distinguishable by the weight. Reproduction pattern glass, carnival glass and Depression glass designs are often not as crisp as the original. The designs are not as easy to see in reproduction products because the edges are more rounded; the design produced by the mold is not as sharp.
Compare the colors. Depression glass colors were primarily shades of pink, blue, yellow, amber and green and the reproductions have not kept the original colors. Look at pieces in an antiques and collectibles mall or at a show to see the original colors. You may even find some reproduction colors there: the blue is too blue and the pink is more salmon.
Feel the surface, look at the shine, check the weight and compare the colors to tell if glassware is a reproduction or an original.