Two articles by David Rudd may be of interest to collectors. David is Director of Art & Collectable Examination at Cycleback (http://www.cycleback.com) in Seattle, and author of the books "Authentication and Forgery Detection of Prints and Antique Photographs" and "Guide to Identifying Early Photographs: a Pocket Manual."

The first article explains a Salvador Dali forgery involving the alteration, by the addition of a forged signature, to an authentic but inexpensive Dali etching: http://www.cycleback.com/vcfeb172002.htm.

The second article takes a look at wire photos, which were real photographs used from the turn of the century to the 1970s to make the pictures in newspapers and magazines: http://www.cycleback.com/vcfeb222002.htm