Early American Pattern Glass is also known as EAPG or Pattern Glass. All EAPG will be pressed, but not all pressed glass will be EAPG. "Early" refers to the manufacturing and does not mean colonial America. Pattern glass was made between 1850 and 1910. It was used in the everyday settings and had to be durable as well as attractive. This may be one of the reasons it is possible to find so many beautiful pieces that are still in useable condition.
Competitors produced similar patterns and had similar pattern names. Thousands of patterns were created. Patterns were designed and carved into a cast iron mold. Hot glass was pressed into the mold with a plunger. The mold was fired at extreme temperatures. Then the mold was removed to allow the glass to cool. Pattern glass pieces often have two to four seams from the mold, but many of the patterns were designed to hide the seams.
Many of the patterns were very simple; but others were very ornate and were designed to imitate the expensive cut glass patterns of the era. Some of the patterns featured full table settings with up to 100 different shapes being offered. Most, but not all patterns included a goblet. Some manufacturers only produced single pieces such as goblets. Some say to be an EAPG design, the number of pieces offered had to be offered in a wide selection merit the "pattern" label and just producing a few pieces bearing the same design is not sufficient to classify the piece as pattern glass.
Most EAPG was made in "sparkling clear crystal." By 1870 flint was not being used in the glass formula. Soda lime was substituted for lead and the cost was greatly reduced , the glass could be pressed thinner, and the clarity rivaled flint. Blue, Canary, and Amber were also produced. Amber was the second most plentiful color and is the least valuable today.