Posted By:
Scott LevyI would agree with the assessment offered and would add the following rarities:
Old Mill Brown (extremely rare....possibly even rarer than the Ty Cobb back)
The interesting thing about the OM brown is that they tend to be either slimmer than the blacks or even hand cut. They are also not immediately distinguishable from the black in all instances, but some show very strongly. Nearly impossible to find and very costly as well.
Lenox Brown (very hard...although not as hard as OM brown). The Lenox Brown back is a color variation on the already quite scarce Lenox back. Somewhat possible to find but very costly.
Blank Back - not quite as scarce as you would think, but still a reasonable tough one. Be careful of 'skinned' backs. Many blank backs are hand cut. These typically start at around $300.
My opinion on the 'best deal' in tough backs is the piedmont factory 42. It's a minor variation to be sure. But only a small fraction of piedmont backs were printed at the factory #42 making it very tough to find (but not very costly on a relative basis). Its possible to pick up a type card for $100.