Jim's Handy, Dandy
Compendium of Philatelic
Flaws and Defects

There are surprisingly few philatelic guides as to what constitutes flaws and defects when one describes a stamp.  The seller of a stamp is obligated to note any flaws, defects, or repairs thereof of which he is aware.  Responsible sellers will gladly refund the buyer's cost for any which have been misdescribed.  The following is an attempt to identify the possibilities and, where appropriate, give some hints on how such problems may be detected.

As a first step, I suggest that the reader read Be Your Own Expert.  It suggests that the questions of condition and identification are not a problem for at least 90% of the stamps which one might encounter if you arm yourself with a catalog and standard philatelic tools.  Of course you need to study the introduction to the catalogue which provides a basic introduction to catalogue use, stamp identification, and condition evaluation.  You might also take a look at Distinguishing Characteristics of Stamps which tries to illustrate many of the features used by the catalogers to separate stamps.

There are two categories of stamp differences which contribute to stamp evaluation given that the stamp is properly identified from the standpoint of catalogue number: Visible Features and Hidden Flaws.  The possibility of repairs or man-made "adjustments" will also be addressed.

Visible Features

Visible features are those which can be assessed by reference to a good scan of the face of the stamp.  This group includes: centering, color (with some qualifications), misregistration, perforations, straight edges, impression, scuffs (sometimes), pinholes (occasionally), grills (possibly), perfins (if properly backed with a contrasting but not conflicting color), missing pieces, stains, soiled, and, if used, cancellation.  A good scan should show up about twice normal size on the viewer's monitor.  This suggests that stamps should be scanned at perhaps 100 dpi and 200% size.  The background should be other than white but not necessarily black.  It is important to choose a background which will not obscure the perforations.  This is particularly important for cancelled stamps.

Since centering is in the eye of the beholder, all that is required for assessment is the scan.  You need not agree with the seller's evaluation.  You can make your own.  Obviously, you want to buy stamps which meet your own standards.  Don't forget that the linearity of your system or the original scan may not be as good as you expect.  A simple way to make a linearity test is to scroll text on your screen and note if there is an area which appears to cause a change in spacing.  If this is encountered, there is clearly a non linearity somewhere in the video system and this needs to be considered when doing an evaluation of centering.

One of the tricks of improving centering is reperforation of stamps which were straight edges or which were copies with wide margins.  There is a good discussion of reperforation at the Philatelic Hall of Shame.  Another repair or faking technique is to combine two stamps by gluing the ample margins and perforations of one on the edge of a stamp which had inadequate margins.  Such stamps are sometimes revealed when the pieces float apart while being soaked to clean up a hinge remnant.

Color is difficult even without the intervention of all the electronics in scanners and monitors.  One of the most likely problems is that your screen is not set up to deliver all the possible colors.  If your monitor driver is only set for 256 colors, you will not see many of the colors well enough for more than cursory confirmation.  The same is true of many scanners which have software adjustments which change the emphasis on the elements of the color formula or scans which have had color adjustments.  Assessment of color based on a scan is not likely to be successful when the shades are subject to confusion when viewed directly.  Examples of stamps in which this occurs are the pink, pigeon blood pink, rose pink, rose, bright rose, dull red, rose red, brown red, pale brown red, lake red, and red all of which are attributed by Scott to the 3 Washington stamp of the United States which was first issued in 1861.  The same observations on color can be applied to cancellation colors.  However, remember that probably 90% of all stamps are not subject to color confusion except for possible changelings.

Changelings are the result of some process which causes the color of the ink to change.  The most likely cause is the  change which occurs as the result of exposure to light.  Strong sunlight can change a stamp's color in just a couple of hours.  The term sun faded applies to stamp colors which appear to be washed out as well as fabrics.  Some colors simply fade with age.  We all have observed how some old inks used for letters have faded until they are hardly legible.  Other causes of color changes result from the effects of chemicals applied to the stamp intentionally or unintentionally.  Many household and other chemicals will cause such changes.  Sometimes only being near the vapors of such chemicals is all that is required.  Be wary of stamps which have abnormal colors.  More often than not such colors are the result of some form of doctoring.

Misregistration occurs when the plates which apply the different colors to a multicolored stamp become misaligned and one or more colors are not precisely aligned.  A good scan should reveal any such misregistration.  Major misregistrations are regarded as collectible errors.  Minor misregistrations may only make the stamp unattractive.  The ultimate variant on this is the Dag Hammarskjold stamp printed by the United States in 1962.  Some stamps were discovered which had escaped the Bureau of Engraving and Printing with the yellow background inverted.  Before the affair was over, the Bureau had reprinted the stamp with the yellow background inverted so everyone who wished could have the "error."  The stamp and the "error" are listed as 1203 and 1204 in Scott.

Perforations should be easily visible in the scan.  The choice of an appropriate background by the seller is important.  Black backgrounds sometimes obscure the perforation teeth of cancelled stamps.   Short perforations which result from tears at the bottom of perforation teeth between perforation holes are certainly defects to be noted.  The concern for short perforations varies .  What is a short perforation for some might be overlooked by another.  Certainly everyone would note if the base of the perforation tooth had pulled out a portion of the paper beyond the bottom of the perforation holes.  Another defect associated with perforations occurs when stamps have been separated with a pair of scissors.  While this was done intentionally on some reprints, it is viewed as a defect by many when associated with normal stamps.  It also may be an indicator of a stamp which has been reperforated or manufactured from a straight edge.  However, many complete booklet panes are examples of stamps which are expected to have straight edges.

Sometimes a stamp which is not normally imperforate has no perforations on one or sometimes two adjacent sides.  These are called straight edges and occurred when sheets of stamps printed were separated into smaller panes for sale.  They also occur on modern stamps where small sheetlets are cut apart for retail sale.  Straight edges (sometimes abbreviated as SE) are considered less desirable by collectors and are sold at a discount.  It should be noted that straight edges are actually less common than the fully perforated stamps from a sheet.  In the case of U.S. flat plate stamps printed in sheets of 400 and cut to panes of 100 for distribution, there are 19 straight edge stamps for every 81 fully perforated stamps.  Review the notes on reperforation at the Philatelic Hall of Shame.

The quality of the impression of a stamp may be visible from the scan.  Early impressions before plates wear are generally best.  Such impressions show clear detail and crisp lines.  This is a good reason for oversized scans.  The lines become less distinct and thinner as the plates wear and the engraved features become filled with dried ink.  Such impressions also occur when the plates have been wiped too heavily and too much ink removed after inking.  Another feature resulting from the printing of engraved stamps is an overall coloration in the stamp color which is really a thin coat of ink.  Such a thin coat of ink occurs when the plate is not wiped well with clean wipes between impressions.

Scuffs arise when something coarse has contacted the stamp and lightened or removed the color in an area.  Scuffs on the face of a stamp should be avoided or at least be given a good discount.  Scuffs are generally visible in a scan.  Conversely, pinholes often are not visible in scans.  The pinhole may be too small or the paper may have been pressed back in place.  These are often not visible except when examined by backlight or in watermark fluid.  At one time, many stamps were offered by US dealers on New York streets from card displays where the stamp was pinned in place!  Pinholes are often pressed and then repaired with some binder (glue).  Such repairs can often be discerned in watermarking fluid or under an ultraviolet lamp.  Some very skilled repairs of scuffs can sometimes be accomplished by experts skilled at mixing paints to match and painting with brushes having a single camel's hair.  Fortunately, the skill and time required for such a repair limits its application to the most valuable stamps for which an expert certificate is probably required anyway.

Proper identification of grilled stamps from scans is difficult at best and generally impossible.  These are occasions to make sure that the seller is competent to evaluate the stamp (avoid the return hassle) and offers a money back guarantee.

Perfins (stamps which have been perforated with initials or symbols to prevent theft from mailers) should be clearly identifiable from a scan which shows a contrasting color background for the stamp.  Sometimes you need to look carefully if you consider such perforations a defect -- most collectors avoid them except for specialists.

A scan should readily identify any missing piece but not necessarily a repair which involves putting a missing piece back on the original stamp -- sometimes even a piece from another stamp!  A dip in watermark fluid will generally reveal repairs of such problems.  The repair will generally show up as a contrasting line in the fluid.  Ultraviolet examination will generally reveal a repair involving glue or other binder.  The foreign material will show up with a distinctly different response to the ultraviolet light.  Sometimes the missing piece is appropriate.  In the case of the early stamps of Afghanistan, stamps were cancelled by tearing off a corner!

Stains and soil should be visible in a scan of good quality.  However, stains may be hidden in the color of a stamp and soil may appear to be just a poor scan.  Always make sure by contacting the seller or pass up the item if you have any concerns.

Cancellations may be evaluated for quality (e.g. smudged vs. crisp, heavy vs. light, socked-on-the-nose vs. face-free) through a scan.  Scarce or unusual cancellations may be a bit more difficult.  Cancellation marks are sometimes added to obscure defects such as tears.  Fake cancellations are often associated with rare or uncommon covers.  Modern covers are probably too much work for the return in faking the cancellations.  One can imagine that it might be worth someone's while to manufacture some old First Day Covers but I would think that such efforts would be more work than they are worth.

Hidden Flaws

This is where the problems really begin.  A scan will only occasionally reveal such flaws.  These flaws include:  gum defects, thins and pinholes, hinge remnants, separations such as cuts and tears, added cancellations, and folds and creases.  Most of such defects will be revealed by careful examination by an informed collector.  Again, such flaws are not a large problem in the vast majority of stamps.

Gum defects: "Original Gum" on early stamps is probably among the most valuable commodities known to mankind.  The desire for "never hinged" stamps also has affected the evaluation of stamps.  To the collector the condition of the gum is subject to a number of flaws which may detract from the desirability of the stamp.  Original gum has a characteristic color and sheen for a particular issue.  The best confirmation is by comparison with copies known to be genuine.  Regummed stamps are the result of active intervention by someone who wanted to improve on the stamp's condition.  Such "repairs" will be dealt with in a later article.  Here we need only mention the typical gum defects which one encounters.

First, there is the hinge mark which comes from mounting the stamp with a stamp hinge.  This can be small and noticeable only with careful examination in strong light at an angle to surface of the gum (Very Lightly Hinged).  In the worst case, hinges can clearly change the gum below where the stamp was hinged (Heavily Hinged or Disturbed Gum).  Disturbed gum can also result from efforts to remove hinge remnants by using so-called "sweat boxes" which expose the stamp to high humidity.  The gum of such stamps will be uneven -- even bumpy.  As with most questions of degree, observers may not agree on the extent, but the fact of hinging probably will not often be in disagreement.  And as those who do not have never hinged collections tell us, few collections show the stamps gum-side up.

Gum breakers are noticeable marks on stamps which have been printed on stamps printed on rotary presses.  The paper which is used comes from tightly wound gummed paper rolls which has a tendency to curl after printing making handling very difficult.  To avoid this problem an additional rolling step was added to the printing process to break the gum and alleviate the tendency to curl.  A number of variants of this process can be seen as the experiments were continued.  As more modern gums have been invented the tendency to curl diminished and the gum breaker steps have been eliminated.  At one time Switzerland, Germany, and some other nations have applied gum with special rolls that provide discontinuities in the gum to eliminate the problem.  Switzerland used a process called "grilled" gum to minimize the curling.  This effect shows through even on stamps which have been soaked unless the stamp is thoroughly pressed.

Another gum defect is gum "skips."  As you might expect, these are normal manufacturing defects where the gum is not applied in some small area on the stamp.  Such flaws should be noted but small, normal areas of missing gum are not major defects.

Thins occur when the paper has been torn in such a way as to leave a thin spot in the paper.  Thins generally arise when a so-called peelable hinge turns out to be not so peelable or is carelessly removed.  Thins can also arise when a mint stamp becomes moistened and sticks to a page either during the hinging process or during some subsequent moistening.  Such spots are often described as hinge thins.  As with most other defects there are degrees by which one can adjust one's perception of the value of an item.  Tiny thins are often described by the largest dimension in millimeters.  Thus a 2 mm thin would be considered tiny or small.  A thin which approximated the footprint of the hinge on the stamp might be described as a medium -- possibly even large -- thin or 6 mm thin.  Larger thins become even more serious -- even to the extent of a thin over the entire stamp often resulting from an attempt to peel the stamp off paper without benefit of soaking.  Large thins are serious defects.  Occasionally one encounters a natural thin which arose during the manufacture of the paper on which the stamp was printed.  These, too, detract from the desirability of the stamp nearly as badly as an equivalent thin created by the carelessness of a stamp collector.

Another variety of thin occurs when a stamp is being soaked and the softened stamp becomes abraded while trying to get the paper off.  Before you know it, you've got a great big thin spot.  It is best to just throw out such a stamp.

Sometimes, in an attempt to avoid leaving a thin, a collector will leave a small piece of hinge attached to a stamp.  This is called a hinge remnant and is a defect which should be noted.  There is the possibility that a skilled worker can remove it and leave the stamp with nothing more than a hinge mark or disturbed gum.  Many collectors, however, leave the hinge remnant to the future.  The area should be checked as sometimes a hinge remnant covers a thin.  Until the hinge remant is removed, the assumption should be made that it covers a defect.

Thins can be detected by holding the stamp up to a strong light or by dipping into a suitable watermarking fluid in a black tray.  The backlighting will show a brighter spot when compared to the remainder of the stamp.  The watermark fluid will show a darker spot in the area of the thin.  Care must be taken to avoid confusion between thins and cancellations.  Often cancellations cover thins and reduce our ability to detect the thin.  The same techniques can be used to find pinholes.

Be wary of used items still on a supposedly original piece of the envelope (on piece).  There should be a good reason for the stamp not having been soaked off the paper such as the association of a town mark with an interesting killer cancel or the desire to retain a complete town mark .  If this is not the case, one should expect that the "piece" covers some defect.

Separation such as cuts and tears may also be detected by viewing against strong backlighting or in watermark fluid.  Careful examination with a magnifying glass may also reveal tears along the edge of the stamp.  Sometimes tears occur within the boundaries of the stamp.  Such tears are called closed tears.  Tears are often described by their length in millimeters.  Tears, particularly those which extend into the stamp's frame, are serious defects.  Tears are often repaired by glue of some sort.  These will be revealed by either watermarking or by examination under ultraviolet light which will causes foreign matter to respond differently to the light.

In the same manner, added cancellations can often be detected by the response of the foreign matter (a different cancellation ink) to the ultraviolet stimulation.  This is certainly useful in identifying cancellations which have been added to conceal a defect.

Folds and creases are often visible during careful examination both with and without magnification.  Watermark fluid may also be used to detect folds and creases.  The defect shows up as a distinct mark.  The worst creases break the fibers which make up the paper and can even lead to ultimate separation along the crease.  Lesser creases only leave a bend in the paper.  The crease of a perforation tip is a lesser problem than a hard fold across the whole stamp.

Rev. 8/13/99 To be continued and updated.  It is hoped that illustrations can be added in the future.

Copyright 1999, James Watson