Griswold called what we collectors have named heat ring just rim or rimmed bottom in their early catalogs. The unmistakable mark with GRISWOLD inside a cross and two circles that Griswold used on most of their pieces is their registered trademark or TM. It has often been called a logo which is not incorrect.
What is a Griswold slant logo?
Griswold Slant logo with EPU and heat ring (1906-1926) EPU is short for “ERIE PA., U. S. A.” It was not unusual that some logos overlapped in that period. Therefore, you can find another Slant Logo with EPU in the period from 1906 to 1926.
How do I tell what year my Griswold cast iron skillet is?
Look for an apostrophe in the Griswold logo. If you find Griswold spelled Griswolds, you have a skillet that was manufactured between 1884 and 1912.
What is a ghost mark on cast iron?
Ghost marks are what can happen when an existing pattern used to make the molds to create cast iron pieces is modified. If a foundry decided to change its markings, or remove markings altogether in the case of unmarked goods, they often did not go to the trouble and expense of creating new patterns.