Watermarks on Stamps
Sometimes the only difference between stamps that look alike is their watermark. Watermarks are letters or patterns impressed into the paper used to produce certain stamps. Modern U.S. stamps don’t have watermarks, but many older ones do, in the shape of a single line or double line U, S, or P. See illustrations below.
To see if your stamp has a watermark, place it face down in a watermark tray, and pour enough watermark fluid over it to cover completely. (Never use water.) The watermark should be visible; how well it shows varies with the stamp. You may not see a whole letter or design, but only part of one. Let your stamp dry completely before removing it from the tray. U.S. watermarks are always letters like those shown. (Many foreign stamps have watermarks in the shape of a crown or other symbol alone or in addition to letters.)
Will using lighter fluid in detecting watermarks affect the gum in any way? If so, what way?
We are not aware of lighter fluid affecting the gum. Lighter fluid has been used for years with no mention of gum disturbance. Mystic recommends using Clarity Watermark Fluid due to it’s non-flammable, non-toxic and odorless properties. Clarity Watermark Fluid is available on our website and it’s what our Processing department uses every day to detect watermarks. https://www.mysticstamp.com/Products/Supplies/LS115/USA/
Is there a publication out there that shows and describes watermarks on stamps
Watermarks are difficult to see. Sometimes it’s only a speck on the stamp.
Check out the Scott Specialized Catalog for US watermarks. For the 2018 Catalog, look at pages 29A-30A in the introduction. https://www.mysticstamp.com/Products/Supplies/KS378/USA/ You may be able to find the Specialized Catalog at the library.
Foreign Watermarks are typically found with the country of issue in Scott Catalog volumes 1-6.
Is there anyway to detect watermarks on stamps attached to envelopes?
Not for US stamps. Some foreign stamps have very prominent watermarks, so it’s possible you’d be able to see them. But, unfortunately, you can’t watermark U.S. stamps attached to envelopes.
Can you detect watermark on stamps on paper?
No, not for for U.S. stamps. But you may be able to for some stamps issued by other countries, as they may have very prominent watermarks.
So I bought Clarity and was wondering after it has been applied, will the watermark be present permanently?
No. As the fluid evaporates, the watermark disappears. You could use your phone camera to make a record of it.
What about the 1908 and 1909 franklin, Washington issue without the 191 watermark?