3c Banknote Find-Double Paper?

I was going through a bag of about 100 3 cent Washington banknote stamps. They were mixed and most still on paper. Most of the on paper stamps were trimmed around the stamp and I didn't feel the need to leave them that way. Overall there was about an even mix of the 4 Scott list numbers of 147-158-184-207. This stamp drew my attention. It refused to lay flat on its own. It also has a brownish paper on the reverse. While separating the stamps by paper and secret marks(ps; it's not a secret anymore) This one has the appearance of porous paper. It also has the secret mark. It should list as a Scott 184. However it has a hard and rigid paper. When I looked at the stamp under magnification I noticed along the perf holes the surface paper was gone about 1 mm and you can see the brownish paper all along the stamp.
I have the first three volumes of "The United States Postage Stamps of the 19th Century" by Lester G Brookman. I was reading about the different papers used by the Continental Banknote Co. and his reference to the double paper variety sounds similar to what I have.
I along with everyone else thinks they have a rare variety. Have a look at this and tell me what you think. Also, this stamp has a tear. Would it be worth sending in for an opinion.

If it is double paper, how could it have been soaked off without coming apart? The coloring on the perf tips looks like the old horsehide glue of the 19th Century, but I'd have to see a better image to make up my mind.

The adhesive used to hold the papers together might not be as reactive to water as solvents used to remove the cancels. I took the scans at 1200 dpi. The scanner I have is old. If you click on the scan it opens up.

Bill, The Continental double paper stamps were from the Charles F. Steel patent (86,952 Feb. 16, 1869). The top layer was a very thin lightly sized tissue paper. They were produced aa a reuse prevention attempts to wash the cancel would cause the 2 sheets to separate and friction would damage the printed face.

About 28 million were issued to post offices from Jan. 1 to April 15, 1875 but most were returned due to delamination of the layer before being sold.

Most off cover copies show separation along the edges and the perfs. This printed image is normally slightly fuzzy because of the lack of sizing. The backing paper should be a hard wove paper slightly thinner than the normal stamp paper used by CBN.

So where does that leave us? Is this a double-paper #158 as cataloged by Scott?

Please bear in mind that I have only seen 2 three cent double paper which is a small sample but the back doesn't look right to me. Is there any separation bany where on the paper showing the top to be tissue thin?

The stamp looks like it has three layers. There is the face. Around the edges you can see a darker intermediate layer. The face paper recedes from the intermediate later. The back layer is brownish with swirls of fibers and thin also. The intermediate layer can be seen from both sides around the perfs and edges. Lester Brookman stated in his book the stamp had the appearance of the soft porous but was rigid and snapped like white wove paper. If the backing is made from hard wove paper then it should snap. I'm wondering if the intermediate layer is an adhesive layer with back and front pressed on it. Also I read that there were 12 or more experimental papers that could have been used. I found a ribbed paper in the mix as well.

Are you positive that it isn't either an old repair of some sort or perhaps soiling amongst the thins? Look to see if it's either two stamps just stuck together or for an adherence from whatever it was attached to previously.

EDIT:
Oh yeah! I see what your seeing now. Around the perforations it looks oily or some such? Could it be where they mended two rolls together or would it be too early for dandy rolls? (or whatever they're called?)

The bottom perfs are the clearest for close-up study. Even 10X power should let you determine if there is only ONE layer of perforation (with the tips stained).

I'm looking at it with a lighted 10x Eschenbach magnifier. The middle or intermediate layer is probably adhesive that has hardened. It looks like there is some fiber in it. I can see some sticking out. Russ mentioned that most stamps were return because they separated. Maybe a second attempt to find a better binder. I can see the paper is lifted in spots from the intermediate material. I measured the paper and it is .006-.007 mm. That is pretty much on par with other stamps. The only thing is the double paper is Scott valued at $100.00 used. It has a tear and a scratch that lowers it value even more. You would think it would have more value used. It's got to be harder to find a fine used copy than a mint one.

Scott has the double paper issued extremely under valued.

The thickness of .006-.007 would be on the low side. The CBN double paper is about .0077 average which would still put a .007 in the low end of range.I do known of several other double paper processes but they all pre-date the CBN printing contract.

I'm sure it is a double paper at this point. However I'm torn on the opinion. The damage is the main drawback. Will this stamp ever be worth the cost of an opinion?

Some delamination of the layers would not be bad. The tears are definitely objectionable. It is hard to gauge the total effect of the condition because they don't hit the market that often.

Bill Weiss will give you an opinion in writing for a modest fee:

www.stampexpertizing.com

One of the characteristics of true CBNCo double paper is that the layers will separate rather cleanly if teased apart correctly. So-called double paper that comes from splitting an ABNCo soft paper, or a CBNCo intermediate invariably tears part way through the separation, or it starts to head into a very thin separation which would cut through before it gets to the edge. Judging from the appearance of the reverse on this one, I am not convinced it is a CBNCo double paper. Gum soaks notwithstanding, there are lots of fibers protruding from the perf tips, and, more importantly, there is a graininess to the paper surfaces on both sides that are more typical of soft paper. Of course, judging from a scan about that is not good enough. One would have to see the actual item to be sure.