Q: I have a Salvador Dali etching of El Cid. There is a certificate of authenticity glued to the back that states it is an original etching. The certificate is from the Collectors Guild of New York City. I’m curious about the value.

A: Salvador Dali was a famous 20th-century Spanish surrealist painter. Besides painting, he also experimented with sculpture, film and photography. In the early 1960s, he was commissioned to make a print series titled “Five Spanish Immortals” and based on historic Spaniards. The five included El Cid. The original etchings were printed in a total edition of 180 on two types of paper, one in black ink and one in sepia ink. Each example of this edition was hand-signed by Dali in pencil on the lower right corner. Many were marketed by the Collectors Guild. In 1968 the Collectors Guild published a new edition of the “Immortals.” For this edition, Dali etched his name into the printing plate instead of hand-signing the prints. Thousands were printed. A rare hand-signed edition sold at auction in 2012 for $250. An etched-signature edition recently sold for $40.