Washington's Headquarters, Newburgh, N.Y. - Issued without gum
On sale at the Philatelic Agency in Washington, D.C. from March 15 through June 15, 1935
As can be seen in the images above, it would be impossible to distinguish the Farley Special Printing from the regularly issued commemorative simply by comparing a single stamp. The key to identifying this Farley Special Printing is the gutter between adjacent stamps, in this case a block of four with a horizontal gutter. Any difference in shade is incidental.
The 3¢ Newburgh Peace Issue Special Printing was issued without gum and no provision was made to add gum to sheets of this stamp, so the presence of gum suggests the stamp is not a Farley. However, it would be a simple matter to remove the gum from the ordinary stamp, so lack of gum does not authenticate the stamp as a Farley Special Printing.
This Farley sheet was issued as a sheet of 400 stamps, printed by the rotary press method, with four panes of 100 separated by gutters. In the very center of this sheet the horizontal and vertical gutters crossed, creating a very collectible cross-gutter block with a "cross" or "crossed dashes" at the intersection of the horizontal and vertical gutters.