As a blacksmithing tool, a fuller is a type of swage. A swage is a tool that has a particular shape forged into its surface, which is used to imprint that shape into the metal. Swages are often tools with handles and various shaped heads, which are placed between the hammer and the workpiece, allowing the smith to work the steel into various shapes that would be impossible to make with a hammer alone. Swage blocks are often anvil-like blocks with various shapes forged in them, also for forming metal. The term "swage" is from the Old French "souage", meaning "decorative groove" or "ornamental moulding".