you should post a picture with the signature detail and the edition number and any other thing. Picasso was , like Dali, fond of letting anyone produce hackneyed work and he would sign (or even worse, his wife would sign) the edition "in the print margin" but not "in the stone". Then some litho house would run an ungodly number of the prints as lithos and Picasso had NOTHING to do with em. He was famous for this in his many series of bulfighters and for his "Don Quixote" prints.
Picasso was not above a little larceny and was living off his name at the end. He also did a whole batch of ceramics where he painted a few and had workmen come in and decorate tens of turned pieces.
Dali was worse though. He just signed hundreds of blank sheets and had no idea what was printed on em. cause he was totally senile