Why

[msgtdavid]

Why would someone want to watermark a stamp that is known not to have a watermark?

Comments.

[annadryl]

Context?

All that comes to mind is that someone would be trying to make a (counterfeit) rare error and dupe someone out of their money. I'm sure it's been attempted, maybe even moreso with grills. I'm sure there was a lot of scepticism about that Z grill at first, like "But that doesn't exist"...

But isn't the watermark part of the papermaking process? I don't think paper can be watermarked later, but possibly can be faked somehow.

Google time...

[malolo]

"Why would someone want to watermark a stamp that is known not to have a watermark?"

Take an unwatermarked stamp and fake a valuable variety of a watermarked stamp, i.e inverted watermark of known watermark, sideways watermark, etc, etc, . Fake watermarks aren't true watermarks but usually impressed designs into the paper which look like a watermark when put in fluid. Anytime you find something that catalogues a significant difference in value always assume the lowest value until higher value can be proven. This actually is more common with fake cancellations where mint stamps are "x" value and used examples are "xxx" value. Much easier to fake cancellations than watermarks.

[billsey]

By 'watermark a stamp' do you mean attempt to add a watermark, or to dip it in fluid to see if a watermark is there? The former seems to be reasonably well covered here, by simulating a watermark you might be able to pass a cheap stamp off as a rarity. If the second, you can often see faults that are otherwise hidden by dipping the stamp in watermark fluid. Thins and added paper are two things that stand out in fluid.

[msgtdavid]

Interesting replies, I find this method to be outstanding to find hidden faults by using the water marking process.