Where Does The US Postal Card Fit??

I've not seen any area designated for the US Postal Cards. Or is this just not an area of interest for the forum?

Reason for my interest is any discussion on watermark detection on the early postal cards other than sticking it in front of a bright light? It's very difficult to see the watermark let alone determining if it's large or small.

Any insight would be welcome.

Thanks.

This is the correct section, we do not have a dedicated section for postal cards.

I am not aware of alternative methods for detecting postal card watermarks other than a strong bright light.
Don

Thanks Don. Wasn't too sure about an alternative method for detecting a watermark. And I wasn't sure if a postal card would stand up to watermark fluid or if that would even work.

There's at least one other method for detecting watermarks on early US postal cards: contact print. When I purchased Dr Gundel's specialized collection of postal cards, it included a few examples of scarce cards with contact prints of the watermarks. As he was a scientist by background, he made it sound a simple process but I've never tried it.

If you Google "contact prints" + "postal cards" a few examples show up under Google images (one of Dr Gundel's is about half way down the first page).

Steve Taylor https://stephentaylor.co.uk

Steve, thanks. The search didn't work for me. But I did find the entry on your web site about Dr Grundel.

I scanned most of Dr Gundel's collection and saved them on a Google Drive folder here:

https://drive.google.com/drive/fold...?usp=sharing

If you go to the UX4UX5 subfolder, scans 116 & 119 show examples of contact prints.
Hope that helps, Steve

Thanks Steve. It might just be that it's Sunday morning!

I can see the folder, but I can't open or view the contents.

Appreciate the try.

Ken

As a postal stationery examiner for APEX, I use a cardboard mask and my Ott light to check for watermarks on US postal cards.

It is theoretically possible to use watermark fluid and a scanner to check for watermarks. The trick is getting the scan before the watermark fluid evaporates. I remember reading an article in an older journal where the watermark fluid saturated card was sandwiched between two glass plates to retard evaporation. I have never tried this method.

Many of the watermarked cards reveal only partial watermarks so a knowledge of how the watermark should look is important. You can get experience in this by examining the watermark on UX1 and UX3.

Older journals also have articles about making contact prints using an X-ray machine. Based on pictures in those articles (mostly authored by doctors), seemed to be very effective. Unfortunately, home X-ray machines are difficult to obtain.

<insert rimshot here>

I've never heard of X-rays being used for philatelic purposes. Are there other examples? This would make a great thread unto itself.