Watermarks On Envelopes

I am going through some envelopes and if one uses the IPSS listings the watermark is a key differentiator. I can find the watermark visually (holding up to bright light) but have an issue seeing the details (such as year) that narrows it down. I have tried watermark fluid and cannot see off angle.

Any tips?

Some envelope watermarks are a real PITA! Difficulty in resolving the watermarks might require a brighter light source or the use of magnification or both. Otherwise, unless figure you have the cheapest variety. Sounds like you might be working on the circular die envelopes?

Yes, all the circular die. The weave of the paper interferes with seeing the smaller info (such as the date) clearly.

Here is an example of watermarks. This handy summary is available from the IPSS website.

Hopefully you have the UPSS 20th century catalog and can differentiate regular and high quality paper. The circular dies ran from 1916 into 1950 making watermarks very important to the specialist. Diagonal dates are used on high quality paper. The dates represent both the paper manufacturer and the contract period. I have several circular die envelopes in my inventory where the date is pretty much illegible and for those they only get a Scott number!

Yes, I have the catalogs and can sometimes sort by size or knife but a few times the watermark is the only difference.

I collect air mail envelopes which have varieties. A bright light is good especially if it is on a holder that can be pivoted to find the best angle for each variety. It still can be difficult. I wish you the best of luck.

I gave up. I was hoping there was a trick with watermark fluid.

There is a trick for watermark fluid but you have to open the envelope completely. Placing the envelope after treating with watermark fluid between two sheets of glass should allow the watermark to be visible longer and even allow scanning. I have not tried this method but it was covered in an article in some journal years ago. Sorry, I don't remember which journal and which year. Perhaps someone at the APRL can help? The APRL is closed until next week.