This stamp also comes in the famous "blue
paper" variety, somewhat rare and unlikely to show up in an
unchecked mixture of Washington Franklins. As a
first check, be certain the stamp is double-line watermarked, all "blue
papers" must be double-line watermarked. Fortunately, double-line
watermarks are hard to miss, if you don't see one the stamp is suspect. If
you think your stamp is the "blue paper" variety, you should have
this stamp certified. The
1¢ and 2¢ "blue
papers" are common enough that the certification cost may seemingly
outweigh the resale value of the stamp, particularly if the stamp is faulty
or poorly centered. Still, we would argue that ALL "blue paper"
stamps be certified, if only for reference.