3rd October 2010
Prints Past / Pin marks were small circular indentations on the side of foundry type
Pin marks on foundry cast type were originally a small circular indentation impressed on the side of a piece of type when the pin ejects it from the mould of an automatic typecasting machine. Early casters produced marks not much larger than 3/32", which were forced deeply into the still soft metal. These pin marks are an important aid in identifying old type. Shortly after machine casting became widespread, foundries began to put their name or trademark on this indentation. In the 19th century, when sizes of type varied slightly from foundry to foundry, identification was necessary for the printer to avoid mixing two otherwise similar founts of type. Pin marks are found on most 19th century type and through changes in trademark design it is possible to get a rough idea of when type was actually cast. Improvements in the casting process eliminated the need of the pin, however type founders included imitation pin mark, which was normally round and found on the side of the cast type.