By Bill Weiss

One of the most common and sad types of submissions that expert services receive are those where the submitter/owner thinks he purchased or owns a specific stamp, but in fact, what he really owns is a “stamp” of much lower value than was believed and which was actually made out of one of the following;
   1. - another stamp different from the one it is supposed to be
   2. - a proof
   3. - an essay
   4. - a specimen
   5. - a counterfeit, forgery or photographic reproduction

The purpose of this article is to try to document for the reader the many of the United States stamps where it is possible to imitate what appears to be that same stamp, using some kind of deceptive alteration(s). It is our hope that by reading the text, then becoming familiar with the matrix which will follow this introduction, you will become more aware and proficient in knowing what to look for when you buy any stamp listed here.

How They Are Made


A. By simply trimming off perforations to imitate a FAKE imperforate stamp (Example – the 10c 1857 stamp Number #35) often has perforations trimmed off to make a fake 1851 10c type 1 (Number #13). And of course, any time a stamp is faked by using other stamps as raw material, that stamp is always much less expensive than the one that the faker hopes will fool a novice. In the case of this example, a #35 catalogs under $100 while a #13 catalogs nearly $1,000.00!

B. By trimming off perforations to imitate a coil stamp. It is common to see sheet stamps with perforations cut off on two opposite sides (or one side + a natural straightedge) to make a fake coil. This is one of the most common types of coil fakes. Another is to alter a booklet pane single stamp (which has a natural straightedge on one side, and removing the perforations from the opposite side. This alteration is easily detected because the watermark orientation on booklet stamps (vertical) is the opposite as on sheet stamps (horizontal).

C. By adding perforations to an imperforate stamp to imitate a coil. Again, a common alteration is to add counterfeit perforations to a fully imperforation stamp on two opposite sides OR by adding perforations to a genuine imperforate Government coil. Those are particularly deceptive simply because the cut edges are genuine, thus the only way to conclude that it is a fake is by being able to identify fake perforations.

D. By adding perforations, roulettes or other means of separation to an imperforation stamp to imitate a more expensive perforation or rouletted stamp. Good examples of this is when perforations are added to a 1c 1851 type IV (Number #9) to imitate a fake 1c 1857 Type IV (Number #23). Big difference in value! Note: this is also commonly done to Revenue and Private Die stamps.

E. By adding design portions to a cheaper stamp to imitate a more expensive variety. Example is the 10c 1851-57 type IV stamps (Number #16, #34) which have a RECUT center frame line at either the top or bottom of the stamp (or both). So the raw material is a Type II or III 10c stamp with the recut portion carefully drawn in. Another common alteration is adding a recut line to the 1c 1857 type II (Number #20) to imitate a fake #23 (type IV).

F. By removing design portions from a cheaper stamp in order to imitate a more expensive variety/type. A common example of this is when a 2c 1916 type III coil (Number #492) has a tiny portion of the ribbons at the sides scraped away to imitate the much rarer type II (Number #491). Sometimes the key identifying factor on the design is relatively small and can be carefully removed and often this alteration must be identified by an expert.

G. By removing a grill to imitate scarcer ungrilled stamps. The most common example of this is the 3c 1869 (Number #114) which has the grill pressed out (something I am told is not very difficult to do…..) to imitate either an ungrilled 1869 3c (Number #114a) or the also-rare 1875 re-issue (Number #125). Detecting pressed-out grills can be very difficult or impossible, so expert advice/inspection is highly recommended.

H. By adding a grill to a lower-priced stamp in order to imitate a rarer grilled stamp. This is a common and dangerous type of alteration. Some of the fake grills in the marketplace are rather good. Again, expert advice is highly recommended when you are considering buying the scarcer grills. The “F” and “G” grills are rarely faked, the “E” on occasion, but the “D”, “Z”, and “A” ,”H” and “I” more often.

I. By adding coloring to the paper in order to imitate a rarer paper color. This is commonly seen in the 1909-11 “bluish” papers (which are really “gray”, not “blue”), as well as in some better Revenue and Private Die stamps where coloring is added to imitate scarcer papers. Both the “greenish” paper found in some Revenues as well as the “pink” paper in the Private Die stamps are faked.

J. By altering the color of the cheaper stamp to try to imitate a more expensive variety. This is a relatively uncommon type of alteration as reproducing the color of another stamp by using a differing-color specimen is not often successful. Sometimes sellers offer common “color changelings” as “rare color errors” because they differ from the issued original stamp, but all they are is a normal stamp with the color altered either by natural (such as sunlight) or artificial (such as with a chemical) means. Some stamps are chemically altered to try to imitate the color of rarer stamps. A couple examples include the 24c 1861 “Steel Blue” (Number 70b) imitated by altering the color of the 1862 24c (usually 78b is the raw product), the 1895 “Vermilion” Postage Dues (Number J29-30) are commonly faked by altering the color of the 1c-2c 1895 (J31-32). The colors are rarely convincing if you are familiar with the real color.

K. By adding or removing/hiding a watermark. These are not often seen, as it is quite difficult to add a watermark. Sometimes the faker will try to scratch a portion of one of the letters into the paper from the back of the stamp, but that rarely fools anyone. Much more common however, is trying to hide a watermark in one of two ways; by coating the back of the stamp in such a way that it obscures the watermark or by thinning the paper on the back that is directly over the watermark, making it almost impossible to detect the watermark. The first method of obscuring by coating the back is most often encountered in the high value 1895 issues, where by adding a coating and hiding the watermark, the change in value is substantial.

L. By adding or removing an overprint or surcharge. The most common examples are faked Kansas-Nebraska and Offices in China overprints. Fortunately, good literature exists explaining how to identify the fake overprints as well as the raw stamp material normally used to make the fakes. Removing an overprint is less common, but for example, “Facsimile” overprints, which are found on some counterfeit Newspaper and Official stamps are often seen with the overprint scraped off, or a fake cancel applied over it. Same with “Specimen” overprints scraped off or cancelled over the top of the overprint , particularly on the Newspaper and Official stamps but also dangerously so on the 1901 Pan-American stamps, high value 1893-1895 issues, etc. Always check the surface of the stamp with a good power (10X-20X) magnifying glass looking for rubbed spots or abrasions.


A commonly-seen alteration is when counterfeit perforations and/or fake gum is added to a proof to imitate a stamp. Probably the most often encountered are the 1875 Special Printings of the 1857 Issue (Number 40-47), the 1861 Issue (Number 102-111), the 1869 Issue (Number 123-132), the 1869 Regular Issue high values (where fake grills are also added to make the stamps more believable), and others.

INDIA PLATE PROOFS. The paper of an india proof, because it often contains some bamboo fibers and is of varying thickness compared to a wove paper stamp, must be altered to make the fakes seem like genuine stamps. This is accomplished by 1. Coating the back of the proof to give it more thickness; 2. By re-backing it with stamp paper. These altered proofs can usually be detected by the superior impression and color compared to the issued stamps, the counterfeit perforations are usually much sharper than on issued stamps, and the coating or re-backing can be revealed by carefully observing the item in watermark fluid, watching for the variable thickness of the paper. And sometimes the bamboo fibers can be seen under good magnification.

CARD PLATE PROOFS – Because card proofs are thicker than wove stamp paper, the fakes are accomplished by shaving down the back of the proof to make it thinner, then adding counterfeit perforations and/or fake gum. The fakes can be detected because by changing the thickness the proof cannot absorb watermark fluid as evenly or rapidly as a stamp can, and this fact should alert the viewer that something is amiss. Like india proofs, the color and impression are better than issued stamps and the perforations too sharp.

SMALL DIE PROOFS – Because a 1903 (“Roosevelt”) small die proof is printed on a woven paper which resembles stamp paper, an imitated stamp made from a 1903 proof is more difficult to detect than those made from plate proofs on card or india. The 1903 proofs were affixed to gray heavy cardboard pages then attached to an album, so to make a fake stamp, it must first be removed from the gray card, which was once thought to be impossible, but in recent decades it is now known that it can be done. Fortunately, the value of the 1903 proofs makes them less-encountered as imitated stamps.

WOVE PAPER PROOFS – Less commonly seen are stamps made from wove paper proofs, but some exist. One often seen is a trial color proof of the 1856 5c stamp (Number #12TC5) made into an imitation issued (#12) stamp simply by offering it as the issued stamp. The color of the proof is slightly different than the issued stamp, but this one fools many collectors who are unfamiliar with the usual color of the issued stamp (red brown).

ESSAYS – Many essays are as or more valuable than the counterpart issued stamps, but some exist made into fake issued stamps. There is a small-numeral plate essay of the 1869 stamps which often fools novice collectors when in the issued colors (or close), and many of them are genuinely grilled, so the only really noticeable difference is the size of the numerals. There are 1861 3c Experimental proofs in some colors that closely resemble the issued stamps, so experience is required to recognize these. There are 1870s Experimental proofs on laid paper but in the same colors as the issued stamps which are sometimes represented as issued stamps,but should really fool no-one because of the thicker laid paper, which also exists on slightly tinted papers which is sometimes altered to resemble the issued stamp paper.

SPECIMEN or SAMPLE OVERPRINTS – are sometimes removed or covered over with fake cancels to imitate fake stamps. Most commonly encountered are Officials, Newspaper stamps and occasionally Postage Dues altered to resemble issued stamps. Watch for surface abrasions and fake cancels applied directly over the exact position where the overprints are located, Often the overprint can be seen by dipping in fluid and/or holding it to strong light and looking “through” the stamp.


Some U.S. stamps have been counterfeited or forged, most notably the Postmaster Provisionals, 1847 Issue, some 1857-60 Issues (particularly the 90c (Number #39), and others. A scarcer 20th century forgery is the $2.60 1930 airpost stamp (Number C15) which exists in a rather well done counterfeit. Recently, the Number Specialized catalog started listing some Postal Counterfeits in a separate section, including prices for most of them, even though they are technically illegal to own! A very famous counterfeit is the Sperati Forgery of the 10c 1847 stamp (Number #2) which is so well done that unless you know the few tiny differences in the design from the issued stamp, it is very easy to mistake it.

In recent years as copy machines have made reproducing objects much easier and the product so accurately copied, it was inevitable that some fake stamps would be made. Fortunately, because of differences in the paper from issued stamps as well as the obvious copy dots which can be seen with good magnification, these rarely fool anyone, although we note that a fair amount of different fakes are regularly offered in online venues such as eBay, so caution is advised. Computer-generated images are also problematic, so always be aware that these types of fake stamps exist and if in doubt, always seek expert help or advice.

Faked/Altered List

Following is a list of each United States stamp that is imitated by making it from a different stamp or other raw material as previously described. The list will NOT include stamps that are misidentified and sold as one stamp but are really a different stamp (this is not an alteration). Sometimes stamps are innocently misidentified by sellers and sometimes on purpose, to deceive and cheat the buyer. Also not included are stamps that have had their condition changed by altering the same stamp (such as removing a cancel from a used stamp to imitate/fake an unused stamp, by adding gum to an ungummed stamp, or a cancellation to an unused stamp to imitate a scarcer used stamp, etc).

We are only including stamps or sections of stamps that we have personally seen in altered condition or are listed in a catalog or are well documented somewhere in the literature. The reader will probably be amazed at the number of items listed here that can be altered to try to fool and defraud collectors. The list is as complete as we are able to make it at this point in time. Some sections are listed in groups, meaning that there is no purpose served (for example) to listing each stamp of the Offices in China set showing that they are faked by adding overprints to the 1917-20 regular issue, so to conserve space, the entire set is listed.

Genuine Stamp Fake/Altered Stamp Description Source Material

Number #1

5c 1847 1P1, 1P3, Forgery, Photo. Fake #1 is uncommon

Number #2

10c 1847 2P1, 2P3, Counterfeit, Forgery (Sperati is most often seen). Fakes made from proofs are usually attempts to fake an unused copy. Some crude counterfeits exist that usually do not fool many people. Modern fakes exist either made photographically or by computer.

Number #3

5c 1875 3P2, 3P3, 3P4, Counterfeits. Modern fakes exist

Number #4

10c 1875 4P2, 4P3, 4P4, Counterfeits. Modern fakes exist.

Number #5

Altered 40P1
1c 1851 Type I 40P1, 40P2, 40P3, 40P4, altered stamps (fakers draw/paint In Type I features on Type II, IIIa, IV stamps, cut Perforations off of 1c 1857 Type I).

Number #5A,6,6b

Altered #18
1c 1851 Types Ia,Ib,Ic Altered Type II,IIIa,IV stamps, 1857 Type I w/perforations cut off

Number #8

1c 1851 Type III Altered Type IIIa (by scraping away one center frameline) Altered Type V (by cutting off perforations and/or by adding outer ornaments).

Number #12

Altered 12TC5
5c 1856 12TC5 (several different colors are brownish, but not same as issued stamp), Altered stamp (usually #28 or 29 with the perforations cut off). Colors are different than #12). 41P1-P4.

Number #13

Altered #35
10c 1851 Type I 42P1-42P4, Altered stamp (1857 Type V #35) with perforations cut off. This is a very common alteration

Number 316

10c 1851 Type IV Altered stamp (fake recut line(s) added to Type II-III.

Number #17

Altered #44P1
12c 1851 Altered stamp (perforations cut off 1857-60 12c stamps), 44P1-44P4

Number #18

Altered #40P3
1c 1857 Type I Altered proof (40P3,P4 with perforations added)

Number #21

1c 1857 Type III Altered stamps (outer center line scraped off Type IIIa or Type V with outer side designs drawn in)

Number #23

Altered #9
1c 1857 Type IV Altered stamp (perforations added to 1851 1c Type IV (Number #9)

Number #25

Altered #11
3c 1857 Type I Altered stamp (perforations added to Number #11)

Number #25A

Altered #11A
3c 1857 Type II Altered stamp (perforations added to Number #11A)

Number #27

Altered #28
5c 1858 Brick Red Altered stamp (color of #28, #29 changed and/or Type I design features added to type II stamps)

Number #29

Altered #30A
5c 1857 Brown Altered stamp (type I design features added to type II #30A)

Number #31

10c 1857 Type I Altered proof (42P1-P4 with perforations added).

Number #34

Altered #32
10c 1857 Type IV Altered stamp (Number #32-33 with recut line(s) added).

Number #39

90c 1860 Counterfeit (one of the most widely faked U.S. stamps, many different exist), Essays (few 1901 Shernikow essays can have perforations added to imitate high value “unused” 1857-60 stamps, but these are uncommon fakes)

Number #40-47

Altered #40P1
1c-90c 1875 Special Printing Altered proofs (40-47P1- P5 with perforations added)

Number #63-78

Altered #63P1
1c-90c 1861-1865 Altered proofs (63-78P1-P4 with perforations added (1c,2c,5c,10c,12c plate proofs are from re-issue plates so watch for the “secret marks” on the 2c and 5c values). Experimental proofs (not listed by Number. There are some which are very close to the issued 3c shades and are sometimes offered as issued stamps. Trial color proofs (especially the 1c, but other values as well where colors are close to issued stamps)

Number #79-101

Altered #65
1867-68 Grills Altered stamp (grills added to ungrilled stamps), Altered grills. Essays sold as issued stamps (especially “A” and “Z” grill essays)

Number #102-111

Altered #63P1
1875 Re-issues Proofs (63/78P1-4 with perforations added). The 2c and 5c are very dangerous as they have “secret marks” on the proofs also

Number #112-122

Altered #112P4
1c-90c 1869 Proofs (112-122, 129P2, P3, P4 with perforations & grills added), Essays (Small numeral essays sometimes fool collectors, consult Number Specialized catalog for differences.). Re-issues described as better unused regular 1869 stamps (check Number for comparative values). Lower-value re-issues are sometimes regummed and sold as “no grill” 1869 varieties. Grills pressed out to make fake “no grill” varieties. Expert advice advised.

Number #119b,120b,121b

1867-68 Grills Altered stamps (fake inverted centers exist on the bicolor commemoratives, airmail (C3a) and Revenues). Altered proofs (rarely seen since the proofs are also valuable)

Number #123-132

Altered #122P4
1c-90c 1869 Reissues Proofs (112-122,129P2,P3,P4 with perforations added). Regular 1869 stamps with grills pressed out offered as Re-issues. Fake 3c re-Issues are common and easily made. Seek expert advice.

Number #134-144

Altered #145
1c-90c 1870 “H” Grills Altered stamps (#145-155 (or other Banknotes) with fake grill, Proofs (any P2,P3,P4 can be altered by adding perforations & grill and sometimes rebacking or coating the back to thicken the paper).

Number #134A-144A

Fake Grill
1c-90c “I” Grills Same alterations as 134-144

Number #145-218

Altered #145P2
1873-1889 Banknotes Proofs (stamps made from P2,P3,P4,TC4 with counterfeit perforations and gum are relatively common. A too-fresh and sharp appearance are one giveaway. ESAAYS - (some experimental printings can be confused or used to imitate issued stamps (see Number 156-E2/179-E4). SPECIMEN or SAMPLE overprints removed.

Number #230-245

Modern Forgery
1893 Columbian Set Proofs (P2,P3,P4 with fake perforations and/or gum sold as real stamps) Counterfeits (some exist, generally cruder in appearance than the Issued stamps). Facsimiles (these are sometimes made into fake stamps by placing a fake cancel over the overprint so as to obliterate the facsimile. These also are cruder than issued stamps. Specimens (overprints are obliterated by fake cancel or removed by scraping them away).

Number #246-284

1894-98 Issues Counterfeits (Number lists and illustrates a number of these). Specimens (overprints removed or obliterated on higher values. See Number for comparative values where the issued stamps are of much higher value than with Specimen overprints making it profitable to alter them).

Number 261,261A,262,263

Altered #263P1
1894-98 Issues Altered stamps (watermarks obscured or removed by thinning of #276,276A,277,278). Proofs (261-263P1-4 with counterfeit perforations and gum added).

Number #261A,276A

1894-98 Issues Altered stamp Type I stamp (261,276) with design feature circles around “$1.” Numerals at bottom altered to make Type II.

Number #285-293

Altered #293S
1898 Trans-Miss. Set Specimen overprints removed or obliterated by fake cancel

Number #294-299

Altered #296Sa
1901 Pan-Am Set Specimen overprints removed on inverted center 4c value

Number #300-313

Altered #313S
1903 Issue Specimen overprints removed on high values

Number #314

Altered #300
1c 1908 Imperf Altered stamp (perforations cut off of #300 or off private coil)

Number #315

Altered #304
5c 1908 Imperf Altered stamp (perforations cut off of #304 – a common fake)

Number #316-318

Altered #300
1c & 5c 1908 Coils Altered stamps (perforations cut off of #300, 300b, 304 or added to Imperf 314 or 315 (rarely) or to private or imperf coils (rarely)

Number #320-320A

Altered #319
2c 1908 Imperfs Altered stamps (perforations cut off of #319,319A or private coil)

Number #321-322

Altered #319
2c 1908 Coils Altered stamps (perforations cut off of #319,319A, 319g, 319n or 319p or added to imperf or private coils
NOTE – Hereafter please note that when a coil stamp can be imitated/made from a same- design imperf stamp, that it can also therefore be made from a genuine imperf coil of the same design or a genuine private coil of the same design. In each case, of course, perforations are added (in the case of private coils, the original perforations would be cut off than the fake perforations added. The private coils are rarely seen faked into government coils as there is normally not enough room to do so.

Number #348

Altered #331
1c 1908 Coil Altered stamp (perforations cut off of #331, 331a or perforations added to #343 imperf.)

Number #349

Altered #332
2c 1909 Coil Altered stamp (perforations cut off of #332 or 332a or added to #344)

Number #350

Altered #334
4c 1910 Coil Altered stamp (perforations cut off of #334 or added to #346)

Number #351

Altered #335
5c 1909 Coil Altered stamp (perforations cut off of #335 or added to #347)

Number #352

Altered #331
1c 1909 Coil Altered stamp (Perforations cut off of #331, #331a or added to #343 imperf)

Number #353

Altered #332
2c 1909 Coil Altered stamp (Perforations cut off of #332, #332a or added to #344 imperf)

Number #354

Altered #334
4c 1909 Coil Altered stamp (Perforations cut off of #334 or added to #346 imperf)

Number #355

Altered #335
5c 1909 Coil Altered stamp (Perforations cut off of #335 or added to #347 imperf)

Number #356

Altered #338
10c 1909 Coil Altered stamp (Perforations cut off of #338). Since there is no imperf 10c stamp, any copy that has a genuine line present MUST be a genuine #356 coil stamp as the line was trimmed off of sheet stamps.

Number #357-366

Altered #331
1908 Bluish Altered stamps (fake bluing, toning or soiling of paper) of Number #331-340 papers is encountered. They are rarely convincing. Purchase low values (#357- 358) inexpensively (certified recommended) to use as reference. Because bluish paper is made from 35% rag stock, the watermarks show much heavier than on #331-340 – a feature that fakers cannot duplicate.
Number #368, 371, 373 Altered #372 1909 Imperfs Altered stamps (made from #367, 370, 372)
Number #369 Altered #367 2c 1909 Bluish Altered stamp (Made from #367, see comments for #357-366)
Number #385 Altered #374 1c 1910 Coil Altered stamp (Perforations cut off of #374,374a or added to #383 imperf)
Number #386 Altered #375 2c 1910 Coil Altered stamp (Perforations cut off of #375, 375a or added to #384 imperf)
Number #387 Altered #374 1c 1910 Coil Altered stamp (Perforations cut off of #374, 374a or added to #383 imperf)
Number #388 Altered #375 2c 1910 Coil Altered stamp (Perforations cut off of #375, 375a or added to #384 imperf)
Number #389 Altered #376 3c 1910 Coil Altered stamp (Perforations cut off of #376). No imperf 3c single-line watermark exists so the side perforations MUST be genuine and so only the top & bottom cut edges must be authenticated, but this is one of the most commonly faked coils, so absolutely must be authenticated.
Number #390 Altered #383 1c 1910 Coil Altered stamp (Perforations added to #383 imperf – There is no Perf 8.5 sheet stamp)
Number #391 Altered #384 2c 1910 Coil Altered stamp (Perforations added to #384 imperf)
Number #392 Altered #383 1c 1910 Coil Altered stamp (Perforations added to #383 imperf)
Number #393 Altered #384 2c 1910 Coil Altered stamp (Perforations added to #384 imperf)
Number #394 Altered #483 3c 1910 Coil Altered stamp (Perforations added to #483 (And fake watermark added)
Number #410 Altered #408 1c 1912 Coil Altered stamp (Perforations added to #408 imperf)
Number #411 Altered #409 2c 1912 Coil Altered stamp (Perforations added to #409 imperf)
Number #412 Altered #408 1c 1912 Coil Altered stamp (Perforations added to #408 imperf)
Number #413 Altered #409 2c 1912 Coil Altered stamp (Perforations added to #409 imperf)
Number #423A, 423B, 423D, 423E Altered #406 1914 Compound Perfs All are great rarities which must be certified to be collectible. Imitations are made from Perf 12, Perf 10 and imperforations by cutting off or adding perforations or both.
Number #441 Altered #424 1c 1914 Coil Altered stamp (Perforations cut off of #424, 424d or added to #408 imperf)
Number #442 Altered #425 2c 1914 Coil Altered stamp (Perforations cut off of #425, 425e or added to #409 imperf)
Number #443 Altered #424 1c 1914 Coil Altered stamp (Perforations cut off of #424, 424d or added to #408 imperf)
Number #444 Altered #425 2c 1914 Coil Altered stamp (Perforations cut off of #425, 425e or added to #409 imperf)
Number #445 Altered #426 3c 1914 Coil Altered stamp (Perforations cut off of #426 or added to #483 imperf and fake
Number #446 Altered #427 4c 1914 Coil Altered stamp (Perforations cut off of #427)
Number #447 Altered #428 5c 1914 Coil Altered stamp (Perforations cut off of #428)
Number #449 Altered #453 2c 1915 Type I Coil Altered stamp (Type III design scraped ribbon lines to make fake Type I). No effective fakes can be made of most of the rotary coils. Scraping of Type III ribbon lines can usually be easily detected by careful examination with strong (10-15X magnification). To fake 449, perforations must be cut off the sides of #453 and added at the top. 1916-17 coils cannot be successfully used because they are not watermarked, so detection of any fake should be easy. Earlier coils cannot be successfully used because they are printed by Flat Plate, not Rotary. Watermark on #453-459 is vertical whereas on all other 1908-1915 coils, it is horizontal (an important feature to watch for).
Number #453 2c 1915 Type I Coil Altered stamp (same alteration as #449)
Number #454 2c 1915 Type I Coil Altered stamp (same alteration as #449)
Number #456 Altered #493 3c 1916 Coil Altered stamp (Watermark added to #493)
Number #459 Altered #453 2c 1915 Imperf Coil Altered stamp (perforations cut off #453, 454, 455, 487, 488, 492 can all be altered to imitate #459). #491 can also technically be altered to a #459 but is too expensive to use as raw material.
Number #461 Altered #409 2c 1915 Perf 11 Altered stamp (perforations added to imperf #409). Color of #461 is normally pale and many fakes are incorrect shade. Sometimes unwatermarked perf 11 (Number 499) is thinned to fool buyers into believing that the watermark is in the thinned area! If watermark is not clear, avoid the stamp.
Number #463-478 Altered #483 1c-$1.00 1916 issue Altered stamps (#498-518 perf 11 stamps are sometimes reperfed 10 to imitate the earlier stamps). Also #483 imperf with perforations added imitates #464.
Number #467, 505 Altered #466 5c Error of Color Altered stamps (rarely the fakers will try to alter the blue color of #466 or #504 to imitate #467 or #505, but these are not convincing)
Number #476A #439 Used 30c Perf 10, no watermark Wrong stamp (#439 is very often offered as #476A because the watermark is difficult to detect. Since no used copy of 476A has ever been certified, they can be easily discounted. Certification of unused copies is required for consumer acceptance.
Number #482A #482 2c 1920 Type Ia Altered stamp (perforations cut off #500 and fake Schermack Type III perforations added). Note this stamp only is reported with private Schermack Type III perfs, so it can only be imitated as noted here. 99.9% of the stamps suspected by owners of being 482A are merely #482. Expert certification mandatory for buyer acceptance.
Number #500 #499 2c 1919 Type Ia Wrong stamp (this stamp cannot be faked but it is frequently misidentified (is really #499, Type I, not Type Ia).
Number #519 Altered #344 2c 1917 Perf 11, Double-line Watermark Altered stamp (made by adding perforations to #344). Note – This is a very common fake. Expert certification advised
Number #528A Counterfeit 2c 1928 Type VI Counterfeit stamp (Printed by copper plate engraving rather than by the offset method used for genuine stamps).
Number #531-535 Altered #526 1c,2c,3c 1920 Imperfs Altered stamps (all can be faked by trimming the perforations from #525-528B). Most commonly faked are #533 (Type V) and 534B (Type VII). 534B is also often faked by trimming the perforations off a genuine 534B with Schermack Type III perfs. As a general rule, imperf 20th century stamps must measure at least 20.5mm wide X 25mm high and have no traces of a centerline present (as CL copies often have a wider-cut margin on the lined side which affords more room for faking).
Number #539 Altered #492 2c 1919 Perf 11x10 Type II Altered stamp (Type III (#540) has ribbon lines scraped to make TypeII), #492 with fake perforations added and #491 (although rather implausible as #491 is too valuable to use as raw material unless faulty/unattractive.
Number #544 Altered #486 1c 1922 Rotary Perf 11 Altered stamp (perforations added to #486 coil or #542 with perf 10 side re-perfed to perf 11)
Number #545 Altered #490 1c 1921 Rotary Perf 11 Coil Waste Altered stamp (perforations added to #490 coil or #538 with perf 10 side reperfed to perf 11).
Number #546 Altered #492 2c 1921 Rotary Perf 11 Coil Waste Altered stamp (perforations added to #492 coil or or #540 with perf 10 side reperfed to perf 11)
Number #578 Altered #597 1c 1923 Perf 11x10 Altered stamp (perforations added to #597 coil)
Number #579 Altered #599 2c 1923 Perf 11x10 Altered stamp (perforations added to #599 coil)
Number #594 Altered #597 1c 1923 Perf 11 Coil Waste Altered stamp (#578 with perf 10 side changed to perf 11 and #597 coil with fake perforations added).
Number #595 Altered #599 2c 1923 Perf 11 Coil Waste Altered stamp (#579 with perf 10 side changed to perf 11 and #599 with fake perforations added)
Number #596 Altered #581 1c 1923 Rotary Sheet Waste Altered stamp (#581 with perforations changed from perf 10 to 11 and #632 or 632a with perforations changed from 10.5 to 11)
Number #599A 2c 1929 Type II Altered stamp (#599 with hair lines at top of head strengthened)
Number #613 2c 1923 Rotary Perf 11 Altered stamp (#612 with perforations changed from 10 to 11 – an unconvincing alteration as there is insufficient margins to reperf this on all four sides)
Number #634A 2c 1928 Type II Altered stamp (#634 with hair lines at top of head strengthened)
Number #658-679 Altered #637 1929 Kansas-Nebraska Sets Altered stamps (fake overprints added to #632-642 – see note in Number catalog about defining gum breaker ID on genuine stamps versus those with fake overprints. Many fakes are not only on the incorrect stamps based on gum breakers but the fake overprint is too crude. This this article to learn more about gum breakerers.
NOTE – From 1932 to date a number of regular-issue stamps have been counterfeited. While possession of these is technically prohibited by law, they are collectible. They are all listed in the Number Specialized catalog in a special section of “Postal Counterfeits” so their listing here would be redundant. Please refer to that catalog for descriptions and values.

NOTE – Some taggants can be removed chemically to simulate/imitate “tagging omitted” errors.
Number #C3a Fake #C3a 24c 1918 Altered stamp (fake inverted centers made by replacing the vignette or simply covering it with another cut-out vignette). Printed, older and modern, fakes also exist
Number #C15 Counterfeit #C15 $2.60 1930 Counterfeit stamp (a creditable fake, listed by Number as “CF1” can be differentiated from the original by the somewhat cruder printing and unreadable lettering in the label at the bottom center of the airship. Printed modern fakes also exist.
Number #E1-E6 Altered #E5S-E 10c 1885-1902 Altered Specimen (overprint removed. This is not a commonly-seen alteration since the Specimen stamps are of good value.)
Number #J1-J4,J15-J21,J38-J44 Altered #J21S Postage Dues Altered Specimen (overprint removed. Not commonly seen, but has been done, especially on J15-21 valued at only $45 each by Number and mint/OG issued stamps are higher (much higher on the higher values).
Number #J29-J30 Altered #J32 Postage Dues Altered stamps (J31-32 with color altered to fake the vermilion color)
Number #K1-K18 Altered #528B Offices In China Issue Altered stamps (Fake overprints applied to Number #498/518, 528B). Suggest using least expensive 1c-2c or any certified copy as your reference
Number #O1 – O83 Altered #O82S Official Issues Altered Specimens (Overprints removed or obliterated and fake cancels added.) Note especially any Specimen that is much less expensive than the issued stamps. FACSIMILE overprints are also altered to make fake issued stamps, especially the high value State Dept. stamps. Paper of the facsimiles is much softer than the issued stamps.

Number #PR1-8

Counterfeit Cancel
Newspaper Issues Counterfeit stamps (these exist in many different colors as well as with fake cancels added. Genuine PR1-8 are perf 12. Fakes are invariably either less or more (Perf 11, 11.5, 12.5). Genuine cancels on PR1-8 are rare and are virtually always heavy brush “paint” cancels, usually in blue, but also in black, and no handstamp cancel is considered genuine on PR1-8. FACSIMILES exist and fake cancels obliterate the overprint. SPECIMEN overprints exist but are too pricy to use as raw material.

Number #PR9-125

Facsimile Removed
Newspaper Issues SPECIMEN overprints (are removed or obliterated by fake cancels to mimic issued stamps. Numerous different FACSIMILE overprints are altered by adding fake cancels to obliterate the overprint. Some types of Facsimiles have the word printed as part of the design and those are easier to conceal than overprints. Altered stamps (especially PR102-113 when made from thinned copies of PR114-125 to hide/remove watermarks. Also copies with back coated to hide watermarks. Although not an alteration, misidentified stamps are commonly offered/sold as higher-valued varieties. Expertizing highly recommended.

Number #R1-R102

Altered #R1c
First issue Revenues Altered stamps (First Issue imperf and part perf issues are extensively faked by cutting off perforations. No expensive imperf or part perf should ever be bought unless certified by an expert service or with the guarantee that you have the right to obtain expert opinion. Altered proofs (perforations added to make fake stamps).

Number #R6e

Altered #R6c
2c Orange Bank Check on Green Paper Altered ordinary R6c by adding green coloring to paper.

Number #R1d / R100d

Altered #R100
First Issue Silk Papers Altered ordinary regular paper by adding fake silk fibers. The fibers found on genuine silk paper are embedded slightly in the paper whereas the faked paper has the fibers on top of the paper surface and it can often be easily seen to be added simply by using a soft eraser to brush it away – thus proving its correct status.

Number #R102 / R150

Revenues Altered proofs (perforations added to make stamps).

Number #R103a / R151a

Revenue Inverted Centers Altered stamps (fake inverted centers are added to normal stamps in Several ways); 1. By affixing a normal vignette in the inverted position OVER the normal vignette; 2. By cutting out the normal vignette and replacing it by adding the inverted vignette; 3. By cleaning/removing the ink of the normal vignette then adding a fake vignette in that space. The last is particularly deceptive and expert advice suggested.

Number #R112b, R115a, R120a

25c 1871 Revenue Faked sewing machine perforations added at a normal R112 with perforations cut off.

Number #R156-160

Altered #PR121
1898 Revenues Handstamps, Overprints, Surcharges altered stamps (altered by adding the overprints).

Number #R184/R194

1900-1902 Revenues Altered stamps (surcharges added or removed).

Number #R264/R723

Altered #R504
1940-1958 Revenue Overprints Altered stamps (Overprints added or altered to a different year).

Number #RB1b/R10b

Altered #RB2a
1871-74 Proprietary Altered stamps (green paper color faked by adding coloring to violet-paper stamps). Altered proofs (perforations added)

Number #RB1d/RB5c

Altered #RB1d
Proprietary Inverted Centers Altered stamps (See R103a/R151a inverted center info)

Number #RB11c/RB18c

Proprietary Rouletted Altered stamps (fake rouletting added to genuine stamps).

Number #RD61-RD66

Altered #RD24
1940 Stock Transfer Altered stamps (fake handstamps added to ordinary stamps)

Number #RD67-RD372

Altered #RD283
1940-52 Stock Transfer Altered stamps (fake overprints added or genuine overprints altered to different year/date)

Number #RF

Altered #RF2
Playing Card Stamps Fake overprints and/or surcharges likely exist but I have not personally seen any.

Number #RJA1/RJ41

Altered #R228
1919 Narcotic Stamps Altered stamps (fake overprints or handstamps added to ordinary stamps)

Number #RN

Altered #RN-A4
Revenue Stamped Paper Altered (color of cheaper types can be altered to look like more expensive types). I recently saw an item submitted as RN-A4 which appeared to be altered from black (common) to blue (very rare).

Number #RO,RS,RT,RU

Private Die Proprietary Stamps Altered stamps (Paper color altered). Stamps on ordinary paper are dyed to make a more valuable variety). Easter egg dye is commonly used to make fake pink paper color. Often the dyed color will bleed onto the perf tips; this is not possible with original pink paper. Paper color of wrappers also sometimes changed from white, to either orange or yellow. Look for uneven coloring as a giveaway of faked color paper. Altered stamps (color “ultramarine” is sometimes faked by bleaching the less expensive blue variety). Altered stamps (rouletting added to imperf varieties to make more expensive variety. Caution advised when rouletted variety is much more expensive. Altered stamps (silk fibers added to ordinary “old” paper to make “Experimental silk” varieType ). Silk fibers are generally slightly imbedded in the paper and cannot be scraped away, whereas those that are added to fake the experimental silk can usually be easily removed by gentle erasing, proving their true status. Altered stamps (fake imperfs). Can be made of those stamps that exist both die cut and imperf by trimming off the die cuts leaving only the design intact, then mounting/affixing it to blank imperf backing).

Number #RS32a,b 1c

Altered #RS33a
Brandreth Imperf Altered stamps (RS33a,b imperforations with fake perforations added). Note that there are other Private Die stamps where the perforated variety is worth more than the imperf variety Type Inspect/check perforations carefully or seek expert opinions

Number #RS74ah

Altered #RS74
1c Dailey’s error of denomination (“$100”. Instead of “$1.00”). This item is faked simply by inking over the period between the “1” and first “0” to alter it to “$100.”