1916, 1¢ green, imperf, electrolytic printing, top plate number 13376 block of six, large margins except closer at right, o.g., F.-V.F. and rare. Scott No. 481 var.  $450. George A. Rose, then superintendent of the Bureau of Engraving and Printing experimented with printing stamps by the electrolytic process. Two plates were used: 13376 and 13377. $0 (Image)