A factory mark is a symbolic marking afixed by manufacturers on their productions in order to authentify them. Numerous factory marks are known throughout the ages, and are essential in determining the provenance or dating of productions.

Factory mark are essential in the area of porcelain

Porcelain

Porcelain is a ceramic material made by heating raw materials, generally including clay in the form of kaolin, in a kiln to temperatures between and...

production especially, where they are sometimes also called "backstamps", and where their absence would make authentification much more difficult.