Determine the makers of china and porcelain by locating a piece's backstamp and using either a guidebook or an online database of maker's marks to match the backstamp with a particular maker. If the piece has a signature instead of a backstamp, consult an expert to both identify the maker and determine if the piece is genuine. Consulting a professional is also necessary if the piece lacks either a backstamp or a signature.
Locating the stamp on most pieces of china and porcelain is relatively simple. The majority of manufacturers place the stamps on the bottoms of the pieces in colors that contrast with the glaze. Rarely, the backstamp is not on the bottom of the piece but either inside the piece's body or elsewhere. Occasionally, manufacturers emboss or etch their marks into the pieces rather than using colored stamps.
Some pieces of china and porcelain feature more than one backstamp, which can be confusing for collectors. Multiple backstamps usually mean that the piece was worked on by multiple companies or craftspeople. For instance, one company may have manufactured and fired the piece, while a second firm decorated and glazed it.
Pieces without any sort of identifying stamps require expert help for identification. Even though these pieces are not explicitly marked, experts can sometimes identify the pieces if the patterns or decorations are associated with particular historical manufacturers.