Some collectors call this series the Fourth Bureau Issue. Others call it the Series of 1922. It starts with Scott #551 and was the move away from the Washington-Franklin heads. The denominations run from the 1/2¢ to the $5 and include several overprinted stamps. With only a few exceptions, this series is easy to identify with the use of a perforation gauge. Good news, you can put your watermark detector away. Watermarks are often difficult to detect and cause collectors some frustration. This series of stamps is not watermarked.

Because there are a lot of stamps in this series, I grouped some of them together in the table to save space. Otherwise, the table would span several pages for very similar stamps that only differ by denomination. Let's dive in:

Scott #Denomination(s) Perforations Printing Gum BreakersNotes
551-573 1/2¢-$5 11 Flat None
575-577 1, 1 1/2, 2¢ Imperforate Flat None
578, 579 1¢, 2¢ 11 x 10 Rotary None Coil waste, used copies more valuable than mint
581-591 1-10¢ 10 Rotary I
594 1¢ 11 Rotary None Rare, stamp design 19.75 x 22 mm.
595 2¢ 11 Rotary None Scarce
596 1¢ 11 Rotary None Very Rare, most copies have Kansas City, MO precancel, stamp design 19.25 x 22.75 mm.
597-603 & 599A 1, 1 1/2, 2, 3, 4, 5, 10¢ Coil, 10 vertical Rotary None
604-606 1, 1 1/2, 2¢ Coil, 10 horizontal Rotary None
631 1 1/2¢ Imperforate Rotary None or I
632-642, 634A, 692-701 1-50¢ 11 x 10.5 Rotary I, II, or III
646 2¢ 11 x 10.5 Rotary II Molly Pitcher overprint
647, 648 2¢, 5¢ 11 x 10.5 Rotary II Hawaii overprint
658-668 1-10¢ 11 x 10.5 Rotary II Kansas overprints
669-679 1-10¢ 11 x 10.5 Rotary II Nebraska overprints
684, 685 1 1/2¢, 4¢ 11 x 10.5 Rotary III
686, 687 1 1/2¢, 4¢ Coil, 10 vertical Rotary III

Identification of this series is pretty straightforward. Only the 1 1/2¢ and 4¢ have two different designs.

Scott #599 and #634 are Type I. These stamps have no heavy hair lines at the top of Washington's head. Scott #599A and #634A are Type II and have three thick hair lines at the top of his head. Identification is easy once you see the two side by side. A good 10x magnifying glass works well.

Fakes are not too prevalent in this series because of the low value of most of the stamps. The coil waste issues, #578 and #579, can be faked by reperforating other wide margin stamps. The perf 11 rotary printed stamps, #594-596, may be faked. They are rare enough that they should have expert certificates. I'm not aware of any fake overprints for the Molly Pitcher or Hawaii stamps but they could exist. However, fakes do exist for both the Kansas and Nebraska overprints.

This is one of the easier series of stamps to identify. A perforation gauge will identify 99% of the stamps you'll encounter.