1917-19 6¢ Washington
The 6¢ denomination covered the domestic rate for mail weighing up to three ounces prior to U.S. entry into World War I. When the new wartime rate for domestic first rate mail increased from 2¢ to 3¢, U.S. #506 fulfilled the postage for letters weighing two to three ounces. Large quantities were issued – greater than all previous 6¢ denominated stamps combined. This was due to the high demand for stamps brought on by World War I and the rate change.
Flat Plate, Perf. 11
The Bureau continued to use the 10 gauge perforation machines on flat plate stamp sheet even after 11 perf. stamps proved successful. In an effort to save money, they used the perf. 10 wheels until they wore out. Beginning in early 1917, stamps produced on flat plate presses were given 11 gauge perfs.
That marked the beginning of the flat plate perforated 11 Series of 1917-19 stamps. Perf. 12 had proven too flimsy, and perf. 10 was too difficult to separate without damaging the stamp, so perf. 11 became a satisfactory solution.
6¢ Washington, issued to satisfy the three-ounce mail rate
Issue Date: March 1917
Printed by: Bureau of Engraving and Printing
Printing Method: Flat plate, using plates of 400 with four panes of 100 stamps
Color: Red orange