Hunting for a rare find is part of the fun when collecting old prints. Firstly, your eye must be trained in recognizing value.
A great way to start is to visit museums, libraries, and galleries specializing in old prints—places where you know you're looking at the genuine article. Ask lots of questions of the people who are in the know. Museums often have old atlases and old botanical books, old books of many interests. Make an appointment as it is possible to spend hours looking through these treasures. From this, you can get a feel for the prints. Read reference books about the areas or artists that you are interested in.
To begin, buy a couple of inexpensive prints to start your collection. You may want to frame them, but first, examine them carefully. Notice the feel, the patina, the aroma of an old print. Look for indications of the hand printing process such as the plate impression from the printing press or ink smudges and signs of age. The quality and texture of the paper is an important identifier as the older paper was has a particular look and feel that becomes easily recognisable. Hold your print up to a strong light and look for a watermark in the paper, the kind you find in quality stationary. Run your (clean) hand across to feel what's there. Use a magnifying glass to identify plate marks and other identifying qualities
Studying the reference books and viewing exhibits is invaluable, but hands-on experience is a must as well.
Related Tag: Antique Print Gallery