Once placed in boxes of laundry detergent or given away at movies, milk glass today is a popular collector's item. Opaque white or tinted blue, light green or pale pink, many pieces of milk glass do not have distinguishing markings. Produced in both Europe and the United States, items with the same design may be made by different makers. For collectors, it is essential to identify hallmarks, distinguish reproductions from replicas and opt for quality originals.
Familiarize yourself with the terminology and makers of milk glass. Specialty books like "The Milk Glass Book," "Collectors Encyclopedia of Milk" and "Yesterday's Milk Glass" are helpful in identifying milk glass hallmarks. Glass collecting magazines such as American Pottery and Glass Reporter also provide useful information. Learn glass terminology.
Look up factory records or catalogs for production dates. Search sites like Pastpaper.com for trade catalogs and vintage magazines. Learn popular designs like Daisy and Buttons or Randolph. Acquaint yourself with manufacturers: Fostoria, Fenton, Westmoreland, Portieux and Vallerysthal.
Gather information from primary sources such as company catalogs, manufacturing directories and newspaper articles. Discuss, share and exchange source information with other collectors. Join glass societies and clubs focused around makers. Sign up for newsletters to find articles on source material and research done by fellow collectors. Enter forums to learn how to distinguish milk glass color: frosted, slag and dead white. Look on e-bay, Fontaines Auction Gallery website, flea markets and used bookstores for old company ads, past auction catalogs and magazines. Seek secondary sources written based on exhibit collections, trade journals or Glass Collector's Digest.
Look on a piece for Fenton's hobnail---white opaque glass with raised bumps. Earlier hobnail had a translucent milky tinge. Later pieces were more opaque. Crest was in production from 1940 to 1980---milk glass with uniform, colored ruffled edges. Variations in colored edges include aqua, gold and peach. Confirm Fenton's mark---an oval with the full name or "F" in a vertical oval on the bottom of dishes. After 1980, a single number followed the name denoting the year.
Check for indications that the piece is from Vallerysthal Glassworks of France. This maker has pieces in bluish white pressed glass. With beautifully detailed designs from the 19th century, the objects are often figural as glass animal dishes or shell patterns. The name, Vallerysthal is an engraved, raised stamp at the bottom of the piece or simply "P.V." In addition, it may retain a sticker at the bottom of a piece as "PV France." There are few painted pieces, but they assist in determining age.
Look for the grape and leaves pattern that characterize the American glasshouse Westmoreland. Other milk glass items are hand-painted with fruit, birds or flowers. A "WG" represents their mark with the "G" overlaid with the "W" in older items. Some pieces had foil labels in addition to the logo. Pieces by Westmoreland are often hand-painted with fruit, birds or flowers. Another distinguishing feature is a rimmed edge of beading.
Check for the original paper label on the bottom of Fostoria pieces. Identify Fostoria by pattern or its familiar etching. Many pieces did not have markings. Striped yellow, green and blue on a red oval with Fostoria denotes this Ohio manufacturer. Fostoria produced items in pastel colored glass. Jenny Lind featured a cameo of the Swedish singer. In the mid 1950s, Betsy Ross had a band of linked leaves above a band of stars.
Distinguish "J" in a diamond, square or at the bottom of an item as the Jeannette Glass Company from Pennsylvania. Look inside glasses to view the reversed "J." The shell pink milk glass, produced for a short time, recognizable for its chevrons or Venetian pattern. On footed creamers and sugar bowls is a design of pressed pears against grape leaves. The Windsor design retains beaded trim on the outer rims and along the bottom of footed pieces.
Companies that acquired molds from a defunct company may still contain original marks. Productions of replica milk glass resemble the original milk glass but are from different manufacturers.
Never remove paint on milk glass, even if slightly worn. It is an effective method for determining age.