Public domain
Two-way 400-subject postage stamp perforating machine at the United States Bureau of Engraving and Printing
From the collection of Library of Congress. Free to download, adapt and use — no permission needed.
Credit lineTwo-way 400-subject postage stamp perforating machine at the United States Bureau of Engraving and Printing. 1938-01-01. Rothstein, Arthur. Farm Security Administration/Office of War Information Collection, Library of Congress. Public domain.