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

Reviving this thread as I have another cover and a new scan using a scanner with the ability to scan negatives. I can tell from this scan that this Large Queen stamp is on the vertical weave Bothwell Paper. But can anyone spot a watermark?

Jim..I think I can see it..BTW one of our friends who I will not say his name but I came with him to the BNAPS meeting one night says if you hold the cover just right and shine a good light on it, you can see watermarks..Have not been able to do that yet...so sad.

Robert.

I can detect the vertical weave in the Bothwell paper using this method but have not been able to see a watermark this way.

Jim, I usually have to go into my scanner program after I scan the image and play with adjusting the histogram and tone curve of the image. These are what they are called in my Epson software and they are accessible under Adjustments in the scanner programing. I don't know if other scanners have this. I usually adjust contrast and darkness to find the watermarks on these stamps. It maybe a bit harder with a stamp on cover but it could work. I don't have an image program which would let me try it with a saved image.

Mike

I have had no success revealing watermarks on stamps on covers with scanners. Loose stamps are no problem.

Removing the stamp is probably the best solution, which I have done. I do not use a hinge to reattach it. For Canadian stamps, I steal the gum from cheap 1950's stamps by rolling a slightly moist Q-tip on the back and then apply it to the stamp from the cover, then stick it back on. You don't need much gum at all, and it looks as if the stamp was never removed.

BeeSee,
"Loose stamps are no problem."
what is your technique to see watermarks from scanner?

Gilles, I use the same as PostmasterGS.

Here is the link:
https://goscf.com/t/15246

I made a new scan using the PostmasterGS method. Looks like a usable method. I don't see a watermark yet but it may not have one. Something in the upper right corner.

Jim...I also tried this method with GIMP (free photoshop alternative) and another program and could not see watermarks.

Robert

Hi Jim, That area in the upper right in your last images does appear to be an inverted and reversed L. It is hard to say as it does not seem tall enough but these watermarks can be tricky to see and the fact this is on cover makes even more so. I think it is the last L in Bothwell. G. P. at the VGG Foundation could probably make a better analysis of this one on his equipment. It would definitely be a good choice to let him have a look at it.