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Stamps may suffer a variety of faults after their issue as a result of improper care over time. Oftentimes, dealers mistakenly overlook faults. But, because catalog values are for fault free stamps, it is wise for a philatelist to assess condition of any purchase on his or her own. An understanding of stamp fault detection is a critical part of the hobby; especially if one is to collect for joy as well as monetary investment. This guide describes valuable techniques for assessing the presence and absence of stamp faults.
Unfortunately over time, stamps develop major and minor faults as a result of mishandling. Faults include thins, tears, and creases - which are known as the BIG THREE. Other faults include stains, paper toning, paper bends, short or missing perforations, scuffs to the face of the stamp, heavy killer type cancels, fading, reperforation of one or more sides, repairs, and paper wrinkles. In the case of unused stamps, heavy gum disturbances and regumming may be considered faults. Essentially, a fault is any "after manufacture" imperfection that has affected the stamp. Faults, depending on the severity, significantly lower the monetary value of most stamps. Often, a stamp with even a very small fault which may be invisible to the naked eye, may (and should) sell for a smaller fraction of catalog value.
Remember, catalog value is for a fault free (sound) stamp. Stamps with significant detracting faults may sell for tiny percentages of their catalog value. Fortunately many faults can be observed with the naked eye. Those that cannot be seen with the naked eye can be seen using other techniques described below.
OBSERVING FOR FAULTS WITH THE NAKED EYE
Make your first attempt at assessing a stamp's soundness by holding it with tongs under a bright white light. At a close distance, observe its front for freshness, faded, or toned paper. A 3X magnifier may help. Go to the perforations. They should be even and none of them missing ("pulled"). A slightly short or blunt perforation is not too much of a concern, but one that quickly draws your eye by its shortness or missing, affects value. Observe the stamp's cancel. It should be clean and not unsightly. A stamp cancel that is so heavy it shows through to the back of the stamp is considered heavily canceled and may be a significant fault depending on severity. Next, observe the ink of the design and be sure there are no scuff marks on the face of the stamp. Use the bright light and hold the stamp at a variety of angles while doing this. Next hold the stamp up to the bright light. The stamp should distribute light through it evenly. Any brighter spots indicate pinholes, thin spots, or natural paper translucencies. Pinholes are a major fault, and resulted from the ancient days of stamp display using surgical needles and corkboards. Thins tend to be uneven and result from tearing caused by a hinge, gum sticking, or paper removal. The brighter any area, the deeper and more serious the thin spot. Natural translucencies tend to be round and smooth. Since they are natural and formed in the paper during manufacture, translucencies are not faults and tend only to lower a stamp's value if they are large and unsightly. Now turn the stamp over and observe from the backside. Creases and wrinkles may be obvious, or show when the stamp is observed at a variety of angles under bright light. They show as shadows when the angle and your eye are just right. Next, carefully examine the edge of the stamp for any paper tears. Tears may be open, small or large, or sealed. Take considerable time when looking for tears since they are very common.
OBSERVING FOR OTHER FAULTS USING WATERMARK FLUID
After taking these steps one may wish to "dive deeper" and look for sigificant faults not easy to see with the naked eye. A black plastic or ceramic tray (watermark tray) and a watermark fluid will be required. Many dealers and collectors use RONSONOL lighter fluid (in the yellow bottle available at many super department stores near lighters/tobacco) as a watermark fluid. RONSONOL works great, is very inexpensive, and dries slowly (an advantage). To clarify, watermark fluid is used to observe watermarks in the paper of some stamps, but it is also used to make stamp faults highly visible (contrasted). It does not damage the stamp and may also be applied to mint stamps with gum. Gum is water soluble, and therefore is not commonly affected by watermark fluid. Here is a photo of Ronsonol...
Please note: many watermark fluids made specifically for stamps are considered SAFE for human exposure. These fluids, however, are not commonly available and are costly (typically upwards of $20 if you need a bottle shipped to you). Ronsonol, though inexpensive and easily available, contains Naphtha (which may be carcinogenic). Therefore, Ronsonol should be handled in a well-ventilated area and contact with the skin should be avoided or minimized.
Now, how to use Ronsonol to inspect a stamp: In a well-ventilated area, place the stamp in the black watermark tray (ceramic are best but harder to find than plastic) ... with the backside of the stamp facing up. Place 3-4 drops of fluid, enough to saturate but not flood, over the stamp. Under good light, observe it immediately. Tilt the tray to from side to side to spread the fluid across the stamp evenly. The paper should appear uniform in the fluid. Tears, thins, and heavy creases will appear as DARKER areas that will immediately stand out. This is because the fault allows the fluid to penetrate those areas faster. Any air bubbles trapped under the stamp can be pushed to the edges. You may wish to use tongs to pull the stamp out to see if any dark spots happen to align with the cancel (these dark areas could be cancel ink, then, and not damage). You are not done yet. With the stamp in the tray, continue to watch as the fluid dries (may take a minute or two). A light blow of your breath may help the process along. Just as the stamp nears dryness observe it for any "flashing." Flashing is WHITER lines or areas that indicate faint paper creases, fine wrinkles, tiny tears, or paper repairs. "Flash" briefly is visible right before dryness - because those faults dry faster than the rest of the stamp. The stamp should dry uniformly without any flashing. This is a step many collectors and some dealers overlook. Observing the stamp in this way will detect 95% of faults.
To detect reperforation, one should use a perforation gauge to measure all four sides. The sides should gauge correctly for the issue. In addition, the perforation holes should be parallel with the opposite side perforations. I use a custom made grid outline on a transparent sheet to do this. Although some "experts" may correctly argue that not all perforations are parallel from side to side - perforations not being parallel can be one sign of reperforation. Anything unusual here, or perforations that look unnatural (sizes of the holes different when compared to other sides, or cut perf tips instead of naturally torn) could indicate reperforation.
The above tips will take you far. One may also add a UV (ultra violet) light to the fault detection list of tools. A short-wave and long-wave UV light can show paper faults and repairs, removed cancels (sometimes), as well as painting in of the stamp design. This is a separate topic and usually only relevant to very rare stamps.
While handling stamps one should always use tongs and be 100% aware of what he or she is doing at all times. Carelessly placing a stamp in a mount, album page, or holder can lead to a tear. Tiny amounts of moisture on tongs can lead to a gum disturbance or thin. Never leave stamps in direct sunlight. Most will fade, and some delicate ink shades can fade in a matter of hours (e.g. the 6c and $4 Columbians Scott #235; 244).
With care and experience in observing stamps, anyone can become an expert at assessing a stamp's condition. Doing so is not only fun, but also very wise when protecting one's monetary investment.
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