How Can I Tell If A Stamp On Cover Has A Watermark?

When Ron Brigham had his Large Queen sale, he had some covers that sold as watermarked stamped covers. He even knew what the watermark letters were. But I wonder how he did it. Does anyone know how?

Here's a terrible cover. It has tears, worn edges, the left side is reduced from being ripper open, etc. But the date is NO 17 68 so it is worth checking out the paper type because the early printings have all the scarce paper types.

So I look across the surface of the stamp towards a light and I check the weave pattern and it is Bothwell Paper. The perfs are poor and the design fairly clear so this supports the Bothwell paper theory.

So now how can I tell if it has a watermark without taking the stamp off the cover?

This solution was offered in a Stamporama discussion: http://stamporama.com/discboard/dis...n=20&id=5626

re: Finding The Watermarks of Stamps on Covers

Hi Bruce,
I place the stamp with the back down on the glass bed of the scanner and place some black cardboard over the stamp. I set the resolution on about 300 dpi, that seems to work for me. I set the scanner on grayscale rather than color. Then after the scan is made, I adjust the contrast which adds to the black shades or takes away from the black shades. I find if I play with the contrast I can get enough of the watermark to show to enable me to work it out. Once you get part of the watermark coming out it is often a process of elimination to workout which of the watermarks it cannot be. By this I mean, if you are working with Australian stamps for example, the position of the "A" relative to the Crown or multiple Crowns will tell you what it is. The one I find the hardest to distinguish between is the Australian watermark 8 and watermark 10 (my SG album calls them Watermark A and Watermark C). They both show a single crown over a single "A". The only real different is the width of the crown relative to the "A". Very difficult if you can only get a partial watermark showing.
Hope this helps.
Regards ... Tim.
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Here is a similar discussion on another forum -- scroll down to ghopper02 comments:

https://www.stampboards.com/viewtop...f=29&t=10199

You need a Morley Bright watermark detector. You can find it on ebay, or through major stamp suppliers. They'll have a description. It works pretty well with stamps on paper/covers.

jimjung...If as you say the cover is in bad shape, why dont you remove the stamp from the cover to be able to do a complete watermark test, unless of course. you want to keep the cover intact..?

Robert

Even for very scarce stamps on cover, the practice is, or was, to lift the stamp off by flotation, assess it, and then hinge back perfectly in place. But modern technology might preclude that practice?

bookbndrbob - I'm going to try and get one of those.

wert - the cover is in poor shape but it has the date which is important in this case. Might be worth it but I'd like to use this cover to test if I can get the watermark without removing the stamp.

I already have the complete set with watermarks.

Question..Is it legal/ethical to remove the stamp and replace it back as close as possible to the original spot..Cause we are not really changing/adding/removing anything to the original cover..??

Robert

I'm sure that it is legal for him to remove the stamp and replace it as close as possible. Hinging the stamp back into place should be pretty easy with that cancel.
The ethical question is in not revealing that information. Will that affect the value of this cover? How common is this stamp on Bothwell paper on cover?

If you have a flatbed scanner that will scan photo negatives, that might also work. That's what I use, though admittedly, German watermarks are among the easiest to spot.

PostmasterGS, I have a pretty good scanner but it's not specifically made to scan negatives. Is there a special technique, is it in the scanning software or is it actually part of the scanner hardware that is the difference?

Here's the option screens that I have to work with on my scanner software. I'm gonna try the Black and White and Greyscale options to see what happens.

The scanner has to have the hardware to do it. To scan negatives, there's a lamp in the lid in addition to in the bed.

Here's a thread with photos.

I didn't get anything from this scanner.

Greyscale -



Black and White -

Jim, I had success with my scanner but only with the stamp laying back down with a black background behind it. I tried using it with the stamp front scanned both with black background and white background and couldn't see it. Here are a couple of examples:

PostmasterGS said this a little more obliquely, so I'll tease it out a little bit: a scanner that can scan negatives has a separate light source in the lid, so that a light can shine _through_ the material.

I hadn't thought about using it for this purpose, but that's a great idea! I'll be giving it a try.

Jim, I bet you have a friend who has one with that capability. (or know any serious amateur photographers?)

Actually, my brother is a serious photographer and he always had a flatbed scanner. Now I know why. He has tons of equipment. I'll have to ask him about this. I'm gonna give him a call !

It's taken me a long time to get this done. It took me awhile to get together with my brohter. He did scan the cover and gave me this color scan which I put thru the retro-reveal website to yield these B&W images. Here are some results. I think it defintely shows that the stamp has the vertical weave, typical of the Bothwell paper but I don't see a watermark. Anyone see anything?