Oldies can be goodies even in research books. Pressed glass of the 19th century was an extremely popular collectible by the 1930s and major research resulted in the publication of several important books. More books followed over the years, adding history and pictures and even corrections, but photos, drawings, and stories about the patterns available in old books are often unknown to new collectors. We still use these pressed glass books, all written before 1990. They are all out of print, but may be available at your library or online. First and still best at listing patterns and forms and including sketches of pieces is Early American Pressed Glass by Ruth Webb Lee (1931). By 1958 Alice Hulett Metz had written the first of two books, Early American Pattern Glass and Much More Early American Pattern Glass, each listing 1,500 patterns with a picture, maker, dates, and prices.
John and Elizabeth Welker wrote Pressed Glass in America in 1985. It was concerned with factory history, manufacturers and workmen, methods, and products. It's a good book about the histories of glass and has single pictures of many patterns, but if you want to look up a specific pattern, other books are more comprehensive. In 1990 Bill Jenks and Jerry Luna wrote Early American Pattern Glass. It is a more modern version of the material covered by Ruth Webb Lee and includes pattern names, photographs of pieces, factory dates, prices, and a list of other references for each pattern. Doris and Peter Unitt concentrated on Canadian glass at first, then realized that we all confuse the patterns of United States and Canadian glass, so they listed both. Treasury of Canadian Glass (1969) has photos of hundreds of Canadian patterns, plus information on factories and other glass products like bottles and cut glass. We were excited to see their American and Canadian Goblets in 1971, because there were large, clear photos of hundreds of goblets plus some history and a bibliography. Volume 2 followed in 1975, and there are 1994 reprints of both volumes.