Using A Scanner To Determine Watermarks?

I am allergic to almost all volatile hydrocarbons which includes basically all watermarking fluids. I still however need to check watermarks on my stamps. I have a SAFE Signoscope that I used to use 20 years ago but am hoping that there is an effective technique using a scanner to detect watermarks.

If anyone has been successful doing this (dry, not wet) will you please give a brief tutorial showing scanner settings, etc.?

Anghus,

See this thread for one technique.

PostmasterGS, thank you for pointing me to that thread. After reading through the thread I tried your technique but it does not appear to work, for me at least, for US Washington-Franklin stamps with single-line and double-line USPS watermarks. At one point in the thread it seems you tried it on a Washington-Franklin stamp and were unable to see the watermark as well.

I pulled out my old SAFE Signoscope and gave it a try but that was unsuccessful as well. Not sure what I am going to do now.

Anghus, it may be time to find an apprentice. Is the Clarity watermark fluid also a problem for you?

wkusau, I think you're right. I may have to train my wife to check watermarks for me. I'm not sure if I have ever tried Clarity - I'll have to check the ingredients. I've developed an allergy to almost anything with strong fumes however - CA glue, epoxy (I use to build rockets), and most hydrocarbons. To think I used to use carbon tetra chloride for testing watermarks in my youth. It's a wonder I don't have cancer!

I haven't thought of carbon tetrachloride in a long time but I use to use it too!