Scott 408 Flat Plate

Washington Head
Denomination in Numerals 1¢

Scott 531 Offset

Watermark Check: You must first determine if the imperforate stamp was printed using the flat plate or offset method the 1¢ rotary press imperforate stamp was not issued. If the stamp is offset, it does not have a watermark. If it is flat plate, you must check for the presence of a watermark.

Printing Method Watermark Number Privately Perforated by the Following Companies/Types
Flat Plate Single-line 408 Brinkerhoff I, II, IIa, IIb; Farwell 4A, 4B, 4A5, 5A4; International Vending Machine; Mailometer I, IV;  Schermack III; USAV I, II, III
Flat Plate none 481   Schermack III only
Offset none 531 Schermack III only

see also Private Perforations - Vending and Affixing Machine Perforations

Washington Franklin Identifier Tool