Coil Stamp Authentication Is Too Hard

I have some collections I'm breaking down that are pretty high quality, but there are some mistakes and when it comes to coil stamps I'm just struggling. If it was just a couple, I might just pass them. But I'm dealing with several dozen singles and pairs. If they were all legit (I'm sure they aren't) it would be thousands of dollars worth of material. I've gone through this in the past and had PF certify some. As you might expect some come back fake, some come back legit.

I really don't want to send in dozens of stamps to the PF. I know generally what to look for but I just don't trust myself to get it right. Here are just three examples. (All have double line watermarks) I'm not sure what I'm asking for. I don't want to put them all on here and get you guys to do the work for me. I guess maybe I'm looking for some more insight. I have some certified coils so I know what good perfs look like, but frankly each time I look at these I come up with a different answer. Are there things I should be looking for that are more of a giveaway? Looking for advice more than votes up or down. These were marked as 353,354 and 355.

Ha, with these scanned images I'm noticing some things I didn't see with the magnifier. Looks like trimmed perfs at the bottom of the 2c. The straight edges on the 4c are uneven. Here I am answering my own question. Maybe step one is scanning them all and I will catch some things I didn't see before.

The 2 and 4 cent stamps appear trimmed. Don't know about the 5, perhaps you can see if the edges match using an image manipulation program.

I've often wondered if high magnification can distinguish between an authentic cut/separation and a forger's straight edge exacto knife cut. I don't think original cuts were make by forcing the cut against a hard surface. Perhaps someone with expertization could share some knowledge here.

Is this what you are suggesting? They certainly appear to be parallel.

I would recommend that folks read this article 'How To Spot Faked Coil Stamps' here http://www.stampsmarter.com/learnin...keCoils.html

Then study and learn the 'source' stamps used to make altered w/F coils here
http://stampsmarter.com/1847usa/WFFakes.html
Don

Those are both great sources and I have used them a lot.

I just spent some more time staring at some of these. I think my next step will be to scan them all in. It will be easier to spot some obvious signs of fakeness that way. Then any that survive that round I may be back to post again. The biggest problem I have is often the perfs look pretty good - not great - just pretty good. And it's in that zone where I just don't have the confidence to pull the trigger. But maybe with scans I can cut down the likely candidates enough to send them in to the professionals.

"I've often wondered if high magnification can distinguish between an authentic cut/separation and a forger's straight edge exacto knife cut."

Absolutely. Razors and exacto knives are much too sharp.

Certainly looking with a 10x or a 15x will help a lot once you know what genuine edges look like.

A quick story about coils.

Several years ago I bought a lot that had some very nice coils. I had no delusions about correctly identifying these myself but at the time Bill Weiss offered a $5 identification service and I think after id he would provide certs at additional cost for the ones you wanted certified. I packed up about 25 of my coils and sent them off to Bill. About a week later he sent them all back with appropriate ids and fakes noted. Bill was always a gentleman but he included a little note "Please check my website". When I went to his Web site I saw a big disclaimer "Id service is no longer available for coils, no exceptions!"

After that I stayed away from coils.

Great reference links Don. The term I was looking for was found there:

"Were the cut edges cut with a scissors, knife, paper cutter or ?? The cut edges must have the correct appearance from being cut by the coil slicer blades."

I'll experiment tomorrow with a razor on a common stamp (that has a coil issue also) and compare edges. As revcollector points out, using too sharp of a tool would create too clean of a cut. Of course, there's a lot of other ways to fake these besides trimming perfs as pointed out in Don's links.

It's not just too clean, it looks totally wrong. It looks sliced, in much the same way that fake perfs often look too sharply cut.

Flat plate hand assembled coils were perforated in one direction and then cut into strips of 20 on a perforator modified to cut instead of punch. The strips were then pasted up by hand. Edges should be parallel within about 0.001 inch. Slight irregularities, which I call "hesitation marks", from pushing sheets of stamps through the cutting wheels are often visible at high magnification and should match on both sides of the coil if the edges are compared in Photoshop images scanned at 2400 DPI using select, select similar and layer via copy. Examine enough OK looking flat plate coil perforations and some will start to look good. When that happens, get some sleep and come back tomorrow and look again. It is also possible to check perforation rows in Photoshop to determine if they are parallel. Richard Kiusalas used a jig to keep perforation rows parallel, but left the pins aligned between rows, like a rotary press coils, a useful "tell" if the perforation holes are too clean. Some fakers file perforation holes leaving the backs of holes closes to the design roughed up instead of round. Pressure ridges and pulled fibers are also missing and the perforations may appear filed like tips of a stockade fence. Fake perforation tips are often a bit too wide compared to genuine perforation tips.

The general rule is that most used fakes are trimmed from sheet stamps while most unused fakes are from imperforate sheet stamps or imperforate coils with fake perforations added. No horizontal 4 or 5 cent imperforate coils were issued. The Experts Book lists in detail which stamps can be used to make fake flat plate coils or more expensive flat plate sheet stamps from rotary press coils.

Some good clues here. Thanks to all for your input. I will get back here after doing a more detailed look and let you know how it went.

Scanned at 2400 dps - don't bother to work on these - I'm just posting to show the scale of the challenge. These are heavily reduced and optimized. The actual scans are over 50MB each.

This is going to take a lot of time. I hope at least some turn out to be good.