You will know more about prices and values and will recognize a bargain, or a truly rare piece that you may never see or have the opportunity to acquire again.
A good way to begin is by visiting museums, libraries, and galleries specializing in old prints—places where you you're looking at the genuine article. Read reference books about the areas or artists you like best.
With today's marvelous printing capabilities it is relatively easy to make exact duplicates of any original old print. Frequently a magnifying glass will reveal the regular pattern of dots on a modern photographic reproduction.
Look for signs that an old print would exhibit: wear and tear, spilled printer's ink, a smudge, slightly misapplied watercolor, a plate mark, or a watermark. Again, the more you focus on and know about a particular genre, artist or medium that captures your interest, the better off you'll be.
We are indebted to botanists for beautiful flower prints and other botanicals, and to ethnographers like George Catlin and Karl Bodmer for historical American Indian prints.
Early cartographers have given us antique maps with sea monsters and elaborate embellishments.
The entire process was a very tedious and time-consuming one.