One of these stamps is a genuine stamp and the other(s) is a forgery. Can you tell the difference? If you are having trouble, see the "hints" and answer below.
In the genuine, the perf is 11.5 and the entire stamp is sharper than the forgery.It is printed on white, thin, and somewhat shiny paper. The forgery has large variety of perf sizes and is printed on duller somewhat yellowish paper.