“AMERICAN BANK NOTE COMPANY.” in colored letters with shading to the lower right. The imprint is centered in top or bottom margin and covers only two stamps.
“No.” followed by the plate number are in colored italics and similar in size to those of imprints B2 and B3, but smaller than those on imprint E2. The plate number follows
the imprint in TL and BL positions, and precedes it in TR and BR positions, except on Special Delivery plates, where it always follows the imprint.
Used on plates 31-481, plus 488, 489,495,496,552 of the 1879 issues, plus plate numbers 21-025, 72, 73 of the 1890 issues. In addition, the bottom positions
of plates between 483 and 723 with imprint F1 in the top margin are imprint F (i.e., the serial letter was placed in the top margin only on the banknote issues).