Fenton glassware produced after 1973 can be identified by the presence of a Fenton logo molded into the glass. For glassware produced before 1973, consult books released by Fenton or third-party authors.
In 1973, Fenton began putting a logo on all of its glassware. The logo is usually on the bottom or inside the glass piece. Beginning in 1980, a small number appears under the logo to indicate the decade in which the piece was produced. A piece made in the 1980s has the numeral “8,” with a “9” for the 1990s, a “0” for the 2000s and a “1” for pieces produced starting in 2010. For reference, the Fenton website has a page showing the various logos.
Before 1973, Fenton glass was identified only with a paper label. To aid in identifying older glass pieces, Fenton released three books covering the period from 1907 to 1980. A fourth book covers the 1980s. Fenton dealers originally carried the books, but as of 2015 they are out-of-print. Collectors can still find copies with some searching, however, and several reference guides by other authors can also be consulted. At one time, Fenton was the largest manufacturer of handmade colored glass in the United States, and while most pieces are worth $100 or less, some pieces can be worth over $1,000.