The cancel ink used by early postmasters was generally indelible. Unless a cancel is very light, particularly a very light red, magenta, or purple, it is very difficult to remove cancels applied with a hand stamp, such as circular date stamps (CDS), town cancels, grids, targets, “PAID”, cork cancels, etc.

However, inks used to write with were often not indelible, making them easy to remove. Unfortunately, many stamps were pen cancelled in the classic period. Grills were experimented with in the 1860’sand 1870’s to prevent cancels from being washed off and the stamp re-used. While they actually did a fairly good job, the problem of cleaned cancels was overblown in that period and the process was abandoned.

Too bad no one was prescient enough to foresee the day when removing cancels would become rampant, not for the stamp to be re-used as postage, but to pass it off as unused to collectors at up to 10 or 20 or more times the price of a used stamp.

Removed cancels can still often be detected. Viewing the stamp under a strong ultraviolet light will usually bring out traces of the ink. However, this is about how to protect yourself when buying online, when you do not have the opportunity to examine the stamp in person.

There are a number of danger signs to watch out for:

- The PSE estimates that a significant minority of all the mint no gum (MNG) stamps submitted to it turn out to have had the cancels removed. Therefore, be wary of every MNG stamp being sold on the internet. If you buy MNG expensive items on-line, then be sure the seller offers returns for bad certifications. A really ethical seller will also offer to reimburse the cost of the bad cert as well; after all, it’s his fault you had to pay for a cert to prove he made a mistake, not yours.

- There is often a tell-tale residue of the cancel that can be seen if you look very closely and know what you are looking for. It nearly always shows itself as very, very faint light brown lines on the stamp. Don’t be fooled by a seller’s description of “toning” or “soiling”, if the marks come in straight lines or resemble writing.

- Watch out for overexposed scans or pictures of stamps. They have a tendency to lighten the residues to the point of invisibility, and scans are sometimes deliberately overexposed for that very purpose. You can compensate for this somewhat using PhotoShop or any other picture editing software, or other applications that allow some manipulation of pictures (I use MS PowerPoint, not because it’s better but because I am more familiar with it.) Right click on the picture of the stamp, click “Copy” and then right-click again and “Paste” it into the application. Keep slowly darkening the picture using whatever feature is available for that. Watch for any residue as described above to show up.

It is also very important to understand what a pen cancel does to the Scott’s Catalog Value of a stamp – it reduces it by 50% or more from the value of the same stamp with a hand stamped cancel.

Thus, do not assume that if a stamp has a normal looking cancel, i.e., a grid or target cancel, an indistinct cancel of any kind, or even an ostensible fancy cancel, that it did not start out with a pen cancel. I have even seen fake town cancels and CDS.

Washing off the pen cancel and adding a fake hand stamped cancel automatically doubles the perceived value of a US classic stamp, and with some of them, we are talking big money. Not only does the fake cancel double the perceived value, it also helps cover the tell-tale signs of the removed cancel.

Here are some examples of removed cancels, before and after. They are all real cancel removals sold on eBay by the same individual, and all the pictures are from the original eBay lots he purchased, altered and then resold. Many have had additional alterations besides the removed cancel.