How to identify a stamp

Comparison checklist

Administration and purpose

Record and compareRecord denomination, currency, inscriptions and any official, postage-due, local-post or revenue wording.

Limits of the evidenceAdhesive format alone does not establish postage use; seals and revenue stamps require separate classification.

Design and separation

Record and compareCompare frame details, lettering and corner marks. Gauge horizontal and vertical perforations separately per 20 mm.

Limits of the evidenceA screen image has no reliable physical scale. Missing teeth or cut margins are not proof of an imperforate issue.

Watermark and paper

Record and compareRecord a watermark only when observed or explicitly documented for the museum specimen; distinguish orientation and partial devices.

Limits of the evidenceA face scan usually cannot resolve watermarks, gum or paper thickness. Do not detach a stamp from its cover.

Printing and overprints

Record and compareCompare line structure, screen patterns, lettering position and overprint relationship with the underlying design.

Limits of the evidenceColour varies with fading, lighting and scanning; dot patterns alone do not distinguish every printing process.

Issue versus postal use

Record and compareSeparate the source's issue date from a cancellation date; retain cover context, plate markings and museum identifier.

Limits of the evidenceA postmark dates use, not printing. Authentication of an overprint, cancellation or altered perforation needs expert examination.

Step by step

1. 1

   Establish the country or postal administration

   Most stamps name their country, but the earliest British issues famously do not, and colonial, occupation and local post issues name an administration rather than a state. Read the currency and the script as well as any name.

   • Country name, or the absence of one
   • Currency unit, which often identifies the administration
   • Colonial, occupation, local or official issue rather than a national one
2. 2

   Place the issue and its date

   Match the design to a named issue or definitive series, then date it by the series rather than by the postmark. A stamp can be used years after it was issued.

   • Definitive series, commemorative issue or provisional
   • Design changes within a series: portrait, frame, inscription
   • Reprints and later printings of the same design
3. 3

   Check the watermark

   Start with a non-invasive view against a dark background or a suitable watermark detector. Do not soak, peel or apply fluids to an unknown stamp; seek specialist advice if the feature remains unclear. Watermark type and orientation separate printings that are otherwise identical, and an absent watermark is itself evidence.

   • Present or absent; if present, the device and its orientation
   • Sideways, inverted or reversed watermarks are distinct varieties
   • Never record a watermark you have not actually seen
4. 4

   Measure the perforation

   Use a perforation gauge and record the measurement for the horizontal and the vertical edges. Imperforate, rouletted and part-perforate issues are separate types, and trimmed or altered edges can imitate a different separation type.

   • Gauge figures, e.g. 14 × 15, not “perforated”
   • Imperforate, roulette, pin-perforate or syncopated
   • Straight edges from booklet or coil production
5. 5

   Determine the printing method and paper

   Line engraving, typography, lithography, photogravure and offset each leave characteristic traces under magnification. Paper thickness, colour, surfacing and gum type are recorded alongside them.

   • Raised ink lines (engraved) versus flat, even ink (litho)
   • Screen pattern under magnification; dots occur in more than one printing process
   • Paper: wove, laid, chalk-surfaced, coloured; original gum or regummed
6. 6

   Read plate, marginal and cancellation evidence

   Plate numbers, check letters, marginal inscriptions and cancellations can fix a stamp to a specific printing or date of use — and, on the classic issues, they are often the whole point of the study.

   • Corner check letters and plate numbers where used
   • Marginal markings if the stamp is from a sheet edge
   • Cancellation type and date: evidence of use, not of issue

Museum specimens for comparison

Compare visible evidence with the museum's documented object. A collection number identifies the museum specimen, not every object of that type; hidden features remain research required.

Smithsonian National Postal Museum · CC0 (Smithsonian Open Access) · Museum source

30c Hamilton single

October 14, 1874

Documented

30c Hamilton single — postage stamp in the Smithsonian National Postal Museum collection (object 1980.2493.792), catalogued by the museum as Scott USA 165. Dated by the museum: October 14, 1874. Depicts: Alexander Hamilton, American, 1757 - 1804. Medium: white wove paper; ink (gray black); adhesive / engraving.

place

United States of America

How to identify

Compare the design, value, colour, perforation or imperforate margins and any cancellation with the Scott number cited above; shades, papers and printings that Scott separates are not distinguished in this entry.

museum object number

1980.2493.792

museum classification

["Postage Stamps"]

Read the full record

Smithsonian National Postal Museum · CC0 (Smithsonian Open Access) · Museum source

1c Washington single line watermark single

1912

Documented

The object is a postage stamp titled "1c Washington single line watermark single," catalogued under the reference Scott USA 405 and classified within the museum's collection as a postage stamp. The documentation notes that identification involves comparing the design, value, colour, perforation or imperforate margins, and any cancellation with the Scott catalogue entry, while specific shades, papers, printings, and distinct inscriptions or legends are not separately detailed in the record. The recorded medium of the stamp consists of paper, green ink, and gum. It is dated to 1912 and associated with the United States of America, though no maker, manufacturing technique, or physical measurements are recorded in the catalogue. The postage stamp is held by the Smithsonian National Postal Museum under the museum object number 2005.2001.123.

place

United States of America

How to identify

Compare the design, value, colour, perforation or imperforate margins and any cancellation with the Scott number cited above; shades, papers and printings that Scott separates are not distinguished in this entry.

museum object number

2005.2001.123

museum classification

["Postage Stamps"]

Read the full record

Smithsonian National Postal Museum · CC0 (Smithsonian Open Access) · Museum source

Undenom Allen's City Dispatch single

1882

Documented

Undenom Allen's City Dispatch single — postage stamp in the Smithsonian National Postal Museum collection (object 2004.2019.6), catalogued by the museum as Scott USA 3L3. Dated by the museum: 1882. Medium: paper (yellow); ink (red). Local posts and private letter carriers operated in American cities in the nineteenth century alongside the federal post, issuing their own stamps for delivery within a town or between cities.

topic

U.S. Stamps

date recorded

1882

How to identify

Compare the design, value, colour, perforation or imperforate margins and any cancellation with the Scott number cited above; shades, papers and printings that Scott separates are not distinguished in this entry.

museum object number

2004.2019.6

museum classification

["Postage Stamps"]

Read the full record

Smithsonian National Postal Museum · CC0 (Smithsonian Open Access) · Museum source

3c Postage Due single

1879

Documented

3c Postage Due single — postage stamp in the Smithsonian National Postal Museum collection (object 2011.2004.36), catalogued by the museum as Scott USA J3. Dated by the museum: 1879. Medium: paper; ink (brown). Scott's J numbers cover postage due stamps, applied by the post office to underpaid mail to show the amount still to be collected from the addressee.

topic

National Stamp Collection

date recorded

1879

How to identify

Compare the design, value, colour, perforation or imperforate margins and any cancellation with the Scott number cited above; shades, papers and printings that Scott separates are not distinguished in this entry.

museum object number

2011.2004.36

museum classification

["Postage Stamps"]

Read the full record

Smithsonian National Postal Museum · CC0 (Smithsonian Open Access) · Museum source

60c Justice Newspaper and Periodical imprint single

1875

Documented

60c Justice Newspaper and Periodical imprint single — postage stamp in the Smithsonian National Postal Museum collection (object 2005.2004.1561), catalogued by the museum as Scott USA PR44. Dated by the museum: 1875. Medium: paper; ink (pale rose). Scott's PR numbers cover the newspaper and periodical stamps issued from 1865 to 1898, used by post offices to account for bulk postage paid by publishers. They were affixed to receipts kept by the post office, not to individual newspapers.

place

United States of America

topic

National Stamp Collection

date recorded

1875

How to identify

Compare the design, value, colour, perforation or imperforate margins and any cancellation with the Scott number cited above; shades, papers and printings that Scott separates are not distinguished in this entry.

museum object number

2005.2004.1561

museum classification

["Postage Stamps"]

Read the full record

Common mistakes

• Dating a stamp by its postmark rather than by its issue.
• Recording a watermark from a catalogue rather than from the stamp in front of you.
• Missing reperforation or a trimmed straight edge, the most common alteration in philately.
• Assuming regummed gum is original: original gum is part of the identification, not a detail.
• Treating a forgery or a facsimile of a famous rarity as the genuine issue — the great classic rarities are forged far more often than they are found.

Identifying the issue is not the same as authenticating a particular stamp or grading its condition. Famous rarities in particular require expertisation by a recognised body; this catalogue describes the issue, not your copy of it.

Practise on these records

stamps

"Return of Peace" issue, Algeria, 1963

1963

The "Return of Peace" issue comprises 8 postage stamps released by Algeria on 6 January 1963. The StampWorld catalogue lists 8 stamps in the issue (StampWorld numbers 395–402), printed in 8 design types. Values and colours recorded for the issue: 0.05Fr multicoloured; 0.10Fr multicoloured; 0.25Fr multicoloured; 0.95Fr multicoloured; 1.00Fr multicoloured; 2.00Fr multicoloured; 5.00Fr multicoloured; 10.00Fr multicoloured. Perforation: 12½. No watermark is recorded. Quantities issued, as recorded: 0.05Fr 5.275.000; 0.10Fr 9.100.000; 0.25Fr 50.800.000; 0.95Fr 5.025.000; 1.00Fr 4.650.000; 2.00Fr 1.500.000; 5.00Fr 400.000; 10.00Fr 240.000.

Documented

Research required

stamps

$2 Alexander Hamilton Beer revenue stamp single

1871

$2 Alexander Hamilton Beer revenue stamp single — revenue stamp in the Smithsonian National Postal Museum collection (object 1999.2018.468), catalogued by the museum as Scott USA REA29. Dated by the museum: 1871. Medium: paper; ink (red brown / black). Scott's REA numbers cover United States beer stamps, used to show that the federal tax on a barrel or keg of beer had been paid.

Documented

Research required

stamps

$2 Columbus in Chains single

1893

$2 Columbus in Chains single — postage stamp in the Smithsonian National Postal Museum collection (object 1980.2493.1639), catalogued by the museum as Scott USA 242. Dated by the museum: 1893. Depicts: Christopher Columbus, Italian, 1451 - 1506. Medium: paper; ink (brown red) / engraving.

Documented

Research required

stamps

$2.60 Graf Zeppelin Passing Globe forgery single

c. 1930-1938

$2.60 Graf Zeppelin Passing Globe forgery single — postage stamp in the Smithsonian National Postal Museum collection (object 0.197716.4), catalogued by the museum as Scott USA C15. Dated by the museum: c. 1930-1938. Medium: paper; ink (blue). Scott's C numbers cover United States airmail stamps. This entry documents a forgery or facsimile, kept as a reference for distinguishing genuine stamps.

Documented

Research required

stamps

$20 Documentary Conveyance revenue stamp single

1862

$20 Documentary Conveyance revenue stamp single — revenue stamp in the Smithsonian National Postal Museum collection (object 1998.2013.3254.1), catalogued by the museum as Scott USA R98a. Dated by the museum: 1862. Medium: paper; ink (orange). Scott's R numbers cover the general (documentary) revenue stamps of the United States. From 1862 the federal government taxed documents such as deeds, contracts, bank cheques and receipts to help pay for the Civil War, and adhesive stamps were cancelled on the paper to show the tax had been paid.

Documented

Research required

stamps

$200 Documentary Internal Revenue revenue stamp single

1862

$200 Documentary Internal Revenue revenue stamp single — revenue stamp in the Smithsonian National Postal Museum collection (object 1998.2013.3258.1), catalogued by the museum as Scott USA R102c. Dated by the museum: 1862. Medium: paper; ink (green, red). Scott's R numbers cover the general (documentary) revenue stamps of the United States. From 1862 the federal government taxed documents such as deeds, contracts, bank cheques and receipts to help pay for the Civil War, and adhesive stamps were cancelled on the paper to show the tax had been paid.

Documented

Research required

stamps

100th Anniversary of the Birth of Sandor Petofi, 1823-1849 issue, Hungary, 1923

1923

The 100th Anniversary of the Birth of Sandor Petofi, 1823-1849 issue comprises 5 postage stamps released by Hungary on 13 January 1923. The StampWorld catalogue lists 5 stamps in the issue (StampWorld numbers 398, 399, 400, 401, 402), printed in 5 design types. Values and colours recorded for the issue: 10+10 Kr slate blue; 15+15 Kr blue; 25+25 Kr brown; 40+40 Kr dull purple; 50+50 Kr purple brown. Catalogue notes on individual values: 10+10 Kr: Perf: 14; 40+40 Kr: Perf: 14. Design: Kovács Erzsébet. Perforation: 12. Watermark: 7. Quantities issued, as recorded: 10+10 Kr 456290; 15+15 Kr 456290; 25+25 Kr 456290; 40+40 Kr 456290; 50+50 Kr 456290.

Documented

Research required

stamps

100th Anniversary of the declaration of independence of Norway issue, Kingdom of Norway, 1914

1914

The 100th Anniversary of the declaration of independence of Norway issue comprises 3 postage stamps released by the Kingdom of Norway on 10 May 1914. The StampWorld catalogue lists 3 stamps in the issue (StampWorld numbers 90, 91, 92), printed in 3 design types. Values and colours recorded for the issue: 5øre green; 10øre red; 20øre blue. Perforation: 13½. Watermark: 2. Quantities issued, as recorded: 5øre 10.275.000; 10øre 10.750.000; 20øre 1.662.000.

Documented

Research required