What Is The Most Reliable Way To View Watermarks?

I established today that I currently possess a total four stamps without watermarks that could possibly be worth a lot of money - two KGV definitives from Great Britain, one definitive from Ireland, and a Queen Victoria issue from Victoria that I've previously discussed on this forum.

Unfortunately, all four are used, which means that the cancellations could be obscuring them. I suppose the odds are that at least two fall into this category (only one has a catalogue listing and so is known to exist without watermark.)

Does anyone know of a 100% certain way of establishing whether they are watermarked or not?

I'm sure experts are able to do this, but what I want to know is HOW they are able to do this. So what's the gold standard in watermark detection, so to speak?

Watermark fluids. Best in a black tray.

As in lighter fluid? Or something specially made for the purpose?

There are other alternatives, but lighter fuel appears to do the trick. You might want to ensure you use the correct stuff.

It would be interesting to hear from those involved in expertising stamps - what approaches do expert committees use, and which is their default for tricky stamps?

Those Irish watermarks can be very tricky.

I have been looking at the safe signoscope. But I remain unconvinced that paying € 207.95 will make watermarks visible that would not be visible without it. The very few examples I have seen were visible anyway, or did not become evident using the signoscope.

'I remain unconvinced that paying € 207.95 will make watermarks visible that would not be visible without it.'

Ditto.

I suppose I would need to see it demonstrated.

As for Irish watermarks, the stamp I have (the 1½d maroon Map) seems not to have the 'se' watermark. Rather, in the top right corner, there are what seem to me to be three small rings. I wish I could make it out more clearly, as it's the only part of the stamp that seems to have a watermark of any kind.

The best method depends on the country, the paper type and the ink color. So there is no one best method. But here are some suggestions.

Lighter fluid and black glass tray. I use Ronsonol and is very common. I was at the PF several years ago and they use it, too. Black glass seems to work better than black plastic.

Evaluating in sunlight seems to work better than artificial light.

Scan the stamp while it is wet with lighter fluid, using a black plastic background. You can manipulate the scan colors or run it through a program.

Programs - Retro Reveal seems to be back on-line but I have not tried the new version. A second program is ImageSleuth. And one of our members, PostmasterGS, has another program on his website; it's called Postmark Reveal.

If none of the above finds a watermark the stamp either has no watermark or you are looking at a Washington-Franklin, and that's a whole other ballgame.

Thanks for the response, Germania.

I had never thought of black glass before, but I also have no idea where I could find any.

I scanned my Victorian stamp this way. I could not see a watermark, nor could anyone else.

This is the thread here:

https://goscf.com/t/64820

I have been recommending these in a number of threads here since 2015


I have not found any black glass furniture coasters on Amazon in years, but you can find them listed on ebay for cheap every few weeks.
Don

Edit: You can also try searching on ebay for "vintage black glass ash tray" and find something useful. (albeit a bit larger than the furniture coasters.)
https://www.ebay.com/itm/285587157550

Thanks, I'll see if I can pick one up.

Jimjamtwo,
I am confused about your methodology, etc. You state:


How did you determne this? In this thread you seem unfamiliar with the most common method of viewing watermarks, namely watermark fluid and a dark dish:


Yet in the thread you provide a link to, you state on 12/3/2018 that on some stamp:


So, if I may pry a bit, just HOW have you determined the watermark status of these stamps you possess? It is considerably harder for members here to help when we don't know your methodology or where the knowledge from 2019 has gone. Sorry, just watched an old episode of "Perry Mason" here.

'In this thread you seem unfamiliar with the most common method of viewing watermarks, namely watermark fluid and a dark dish.'

Of course I am familiar with this method.

What I'm asking if there's a definitive way to verify the conclusions I reached using 'the most common method.'

Although not 100% accurate, these devices might help to validate watermarks:

Lindner Stampscop (probably the least expensive of this group)
Stanley Gibbons Detectamark Spectrum Watermark Detector
Safe Signoscope (strongly recommend the T1 model)

Thanks, Shermae. Do you have personal experience of all three?

Sorry, but reading your posts I see no demonstration of familiarity. Good luck!