According to Essortment.com, Venetian glass makers of the 16th century were the first to invent crackle glass. The glass makers immersed hot glass in cold water, and the glass cracked. After they reheated the glass, it was then hand-blown or molded in the desired shape. This process would seal the cracks of the glass.
One of the primary reasons for creating crackle glass was to hide imperfections. A piece of glass that revealed lines or swirls through it was known as "corded." The glass was then crackled to cover up the imperfection instead of being disposed of.
Numerous states in America manufactured crackle glass from the 1930s to the 1970s. Ohio and Pennsylvania had crackle glass manufacturers but West Virginia was the main producer of the product. West Virginia produces off-hand glass, meaning the glass is mouth blown.
Well-known crackle glass companies in the West Virginia were Bischoff, Blenko, Kanawha, Pilgrim and Rainbow. The five popular companies produced items including cruets, cups, decanters, glasses, jugs, pitchers and vases. Cruets are small bottles with a glass stopper often used for vinegar and oil, and decanters are larger bottles that usually contain liquor. However, as of 2010, Blenko is the lone company that manufactures crackle glass.
On the bottom of its glass products Blenko sandblasted its name with the image of a hand underneath it. Collectors held these items in high regard and sought them out. According to Essortment.com, glass products produced by Pilgrim had "a mark on the bottom resembling a strawberry." The glass makers at Pilgrim made this imprint by tapping a file against the glass while it was hot.