Knives P-10 (lower envelope) and P-11 (upper envelope) compared. The rounded flap of
knife P-10, used in the earlier printings of the 1¢ and 2¢ values contrasts with the
pointed flap of P-11, used in printings to fulfill the order of January, 1889, and all
subsequent orders for these two values. Notice also the difference in the corner angles
where the flap meets the body of the envelope. Knife P-11 has a wider angle.
Back to 
