Srail Test

Continuing my education as a new collector, I comb the threads on this and other forums for interesting topics and came across a number of posts concerning the Srail test for detecting reperforations. A few questions, if I may:

1) What exactly does one look for when one compares left/right sides or top/bottom sides - misalignment of perfs, shape of perfs, variances in the shapes, nonparallel sides, other things? What characteristics would a sound stamp display?

2) What is there in the shape of a perf that might betray a reperf - does this factor vary depending on the stamp?

3) How definitive is this type of test- have there been folks out there who are so expert at reperfing that their product can defeat the test, since they may have known what collectors would look for, even if this particular test hadn't been invented yet?

4) Any other tips on how to use the test/caveats on results/etc.?

Many thanks for your patience and your guidance - I have learned so much in just the week since I registered here and I really appreciate it.

This link here will give you a good overview. I'm sure you'll get some good advice here that goes into much more detail.

http://johnapfelbaum.blogspot.com/2...rations.html

I'll try to answer your questions in order:

1) Check the gauge of the perfs for consistency. I graphically take perfs from one side and line them up with the opposite side (top vs bottom, or left vs. right.) I usually try to match the first 3-4 perf holes as best I can, then look at the other end. If the perfs aren't perfectly matched up at the other side, the gauge is different on one of the sides and the perfs on one of those sides aren't genuine.

IMO, no physical gauge (Kiusalas, etc.) can match the accuracy of this test when done on a high-resolution scan. I can probably detect gauge differences of 0.01 - impossible to see slight differences like that lining perfs up on a Kiusalas.

Also, the sides need to be exactly parallel. If you line up those first 3-4 holes and form perfect circles and you end up with ovals at the other end (even if the gauge is exact,) then the sides are not parallel and one of them is reperfed.

2) Perfectly round & clean-cut perfs are almost always fake. Depending on the quality of the scan, you may be able to see pressure ridges (a characteristic of genuine perfs - lack of them is a red flag.)

3) If the gauge doesn't match, or the sides aren't parallel, the test is near 100% accurate at detecting a reperf, although it won't tell you which side has been altered.

There are expert reperfs out there and the gauge of each side will match precisely and the sides will be perfectly parallel. That's why if it "passes" the Srail test, you still have work to do. You need to look at the shape, cut, pressure ridges, etc. and confirm the perfs are genuine (I use a 25x loupe and at that point would use something like a Kiusalas to confirm the gauge is actually correct for issue.)

In other words, the test can pretty conclusively tell you perfs on one side are fake, but it CANNOT (by itself) tell you the perfs are genuine, only that they MAY be.

4) One (of many) caveats: In order to do graphical manipulations like the "Srail test," the stamp must have been scanned. You can't do these tests from photographs (and lots of ebay lots are photographed.) Also, my comments about perf cut, shape, etc. apply mainly to regularly-issued early USA stamps. Genuine perfs for modern issues, other countries, etc., may have different characteristics.

Hope this helps.

Many thanks to both of you for your very helpful input. I continue to gain much valuable information on this forum.

srailkb - Being new to stamp collecting in general and to this forum in particular, I assume that it's not a coincidence that your user name and the name of the test are similar - given your detailed and in-depth response?

Thanks again.

You're correct...not a coincidence :-)

The development of the test goes back to the 1990's, when I bought my first flatbed scanner -- they were very expensive back then! I recall first mentioning it (along with its potential to conclusively detect reperfs) on the ebay stamp chat board.

My ebay registration date is Feb, 1996 -- undoubtedly one of the earliest "stamp people" to use the site -- but I don't think the stamp chat board got any real legs until several years later... I don't recall when specifically I first posted anything about it, but it almost certainly goes back at least 15 years.

Does anyone know where I can access the srail test? There was a website I had visited a few times with stamp collecting tools, but it doesn't appear to be active anymore.

Thank you for whatever assistance you can provide.

Is that Ken Srail by chance?

yes, srailkb = Ken Srail. While the test may bear my name, I had nothing to do with the website/webpage mentioned in this thread. FWIW, the test is straightforward and can be done with free software like GIMP. There's really no need for a website/webpage, although the online test was convenient and pretty user-friendly IMO. It's a shame it's no longer active.

Thank you and much respect.