I hand sign my portraits and "fine art" photographs. I can usually find an area at the bottom of the composition where the signature will not obscure or distract from the composition. I use India ink and an old-fashion nib pen. I use black, white, or gray ink depending on the image.

I do no sign on the fae of commercial prints- copyright notices are placed on the back of prints or theses legalities are addressed in the contracts with commercial clients.

Nuremberg of limited edition prints? Number art such as etchings, lithographs, woodcuts, and other graphics. etc., are based on the concept that the original plate used in the production will be destroyed after the limited run is produced. Also- in certain kids of graphic-art, prints made at the beginning of the run will be superior in quality to those produced during the middle and the end of the run as the plate wears down. This is why the high value is attached to prints with lower numbers. For example, prints marked 12/100 should sell for a high price that on marked 75/100. A very limited run would have a much more limited product such as 4/20. etc.

In analog and digital photography, vast quantities of prints can be made for one negative or file without any loss of quality so the LIMITATION is based on the destruction of the negative or file or a contractual or ethical promise that no further prints will be produced after the end of the run. Of course, the price or desire for a buyer to invest in a limited edition at a significantly higher price is based on the photographer's reputation and status in the marketplace.

It is NOT a bad idea to sign and number your prints- I think it adds professionalism, prestige, and credibility to your work, in terms of your initial marketing. It's important for you to understand the traditional reasons for and the ethical connotations of limited editions and the accompanying numbering system.