1923 US 2-Cent Harding Memorial Stamp (Scott #613): The Rotary Perf 11 Rarity Explained

In the vast landscape of United States philately, very few stamps generate the combination of excitement, confusion, and significant financial stakes that surrounds Scott #613, the 1923 2-cent Harding Memorial stamp with rotary press perforations 11. This stamp is the kind of rarity that rewards careful study, because understanding it requires understanding the nuances of early 20th century stamp production, and the difference between possessing a common stamp and a genuine rarity can be thousands of dollars.

The Warren G. Harding Memorial Issue

Warren G. Harding, the 29th President of the United States, died in office on August 2, 1923. The Post Office Department moved with surprising speed to honor him: a memorial stamp was issued on September 1, 1923, just weeks after his death.

The design features a portrait of Harding engraved from a photograph, printed in black. The denomination is 2 cents, the standard first-class letter rate of the era.

What makes this seemingly simple stamp complex is the production method. In the early 1920s, the Bureau of Engraving and Printing used two distinct printing processes:

Flat plate press: The original and most common method
Rotary press: A newer, faster method that produced slightly larger stamps due to paper stretch during printing

And within rotary press stamps, two perforation gauges were used:

Perforation 11 (the rarity, Scott #613)
Perforation 10 (much more common, Scott #612)

The Printing and Perforation Matrix

For collectors and investors, the complete Harding stamp matrix looks like this:

Scott #	Press Type	Perforation	Rarity Level
#610	Flat plate	Perf 11	Common
#611	Flat plate	Imperforate	Scarce
#612	Rotary	Perf 10	Uncommon
#613	Rotary	Perf 11	Rare

Scott #613 exists because for a brief period, rotary press Harding stamps were perforated with gauge 11 (11 holes per 20mm) rather than the standard gauge 10. The exact reason for this brief production anomaly isn't fully documented, but the stamps that emerged are genuine philatelic rarities.

Why #613 Is So Often Misidentified

Here's where the complexity becomes commercially important: distinguishing #613 from its common relatives requires precise measurement. The difference between rotary and flat plate stamps shows in the stamp's physical dimensions:

Flat plate stamps (Scott #610): approximately 19-19.5mm wide x 22-22.5mm tall
Rotary stamps (Scott #612 and #613): approximately 19.75-20.5mm wide and taller OR wider (depending on orientation of printing)

The measurement difference is small but consistent and measurable with a standard perforation gauge and a millimeter ruler. Common errors include:

Assuming a perf 11 stamp is #610 (flat plate) without measuring the stamp dimensions
Assuming any well-centered stamp is a premium variety without checking perforations
Submitting examples that don't meet the dimensional criteria

Because of these identification challenges, expertization of claimed #613 examples is essentially mandatory for any serious transaction.

Current Market Values

Condition	Approximate Value
Scott #610 (flat plate perf 11)	$0.25 - $2.00
Scott #612 (rotary perf 10)	$10 - $40
Scott #613 (rotary perf 11) Used	$500 - $2,500
Scott #613 Unused (no gum)	$1,500 - $5,000
Scott #613 Mint NH	$8,000 - $20,000+

The gulf between a #610 (worth cents) and a #613 (worth thousands) is entirely explained by the printing method and perforation gauge, making this one of philately's most dramatic value differentials among stamps with identical appearance to the untrained eye.

How to Properly Identify Scott #613

To confirm a stamp as #613:

Step 1 - Check Perforations: Use a perforation gauge to verify perf 11 (or 11x11). Rotary perf 10 stamps are #612, not #613.

Step 2 - Measure Stamp Dimensions: A true rotary press stamp is larger than a flat plate stamp. Width should be approximately 19.75-20.5mm; height approximately 22.5-23mm. These measurements must be made on a stamp without scissor trimming or perforation damage.

Step 3 - Expertize: Given the value differential, submit any suspected #613 to the Philatelic Foundation or APEX (American Philatelic Expertizing Service). Both have extensive experience with this specific issue and the specialized tools to make accurate measurements.

The Expertization Imperative

The Philatelic Foundation has documented numerous cases of #610 (flat plate) stamps being incorrectly offered as #613 (rotary), sometimes honestly through misidentification, sometimes fraudulently through altered stamps. A certificate from a reputable expertizing service is mandatory for any stamp valued above $500, and #613 is well into that territory.

When buying a claimed #613:

Always demand an existing expertizing certificate, or
Make any purchase contingent on successful expertization
Be deeply skeptical of any stamp offered as #613 without a certificate at prices below catalog value

Historical Availability

Scott #613 was never officially sold at post offices. It appears to have been created during a brief production test or changeover period. The stamps that exist were preserved primarily by dealers and alert collectors who recognized the variety when it first appeared. The total number of surviving examples is not precisely known, but is estimated in the low thousands for used copies and hundreds or fewer for mint examples.

The Investment Case

Rarities of this type, genuine classic US philatelic varieties with clear, documented scarcity, have historically been strong long-term stores of value within the stamp market. The demand base includes both US stamp specialists (who need #613 for complete Harding Memorial collections) and general US philatelic investors who understand the rarity's fundamental position.

High-grade mint NH copies have sold for well above catalog in competitive auctions, reflecting the genuine difficulty of finding this stamp in premium condition.

Final Thoughts

Scott #613 is the kind of rarity that makes philately intellectually engaging. The stamps look identical to common examples, but tiny measurable differences create a value differential of several orders of magnitude. Understanding this stamp means understanding something real about how early 20th century US stamps were produced, and owning a properly certified example means owning one of the more legitimate rarities in American philatelic history.

Just remember: always expertize before you buy.

Browse all Stamps →