Stamps On Covers

I have been collecting for many years, mostly 1850 - 1900 year stamps. Question is: I have thousands of covers mostly from 1860 - 1890. How do I check stamps for grills, watermarks, etc. while on the cover. I don't want to destroy the covers, since they contain many rare cancellations, and such.
Any help would be appreciated.

Hi, kennyhorne. I would use the most obvious methods first. Use a process of elimination by Studing and comparing of the same apparent type of stamp the design elements (Scott US Specialized Catalog has a great study of this for US stamps in its introduction pages. But gathering specialized catalogs from all countries of the world would be impossible. Minkus Catalogs borrow from some of the foreign catalogs, so that would be a help. At some point, Minkus expanded into more than two volumes, I don't know when. Get yourself a complete, used set of Minkus World Catalog that are as in good shape as possible, and are of minimum volume size in order to conserve on space that you can afford, preferably with no inventory notations from the prior owner. Get yourself likewise used one-volumne complete copies of the more easily specialized catalogs: Facit covers about 5 Scandinavian), the types of printing used (engraved, litho, typo, etc.,), the size of the frame (some stamps were issued say 30x24.5, and then again 29.5 x 25.6) color, perforations (that's why that little open space is in the perf gauge, to gauge stamps on cover, in albums) and cancellations. Use a good glass and rotate the cover under a good light for paper and silk fiber or in the case of any grills, to see where the shadows fall, just as astronomers view images of the moon and planets in one-dimensional perspectives.

I beleive there is a watermark system available that would determine watermarks on cover, it might be the Morely-Bright system.

Putting a stamp on a scanner and enlarging it would be a big help also. It will help determine paper in some cases, like granite paper (for example stamps of Switzerland), beyond the use of a glass. The obverse of a stamp outside of the frame has very little free space to examine under a glass.

Join a philatelic organization large enough and with wide enough interests to have an extensive enough library. Borrow specialized catalogs from them, get access to specialized stamp journals containing printing variety studies of the stamps you have. And take notes on what you read.

Once you have exhausted all of these methods, submit the cover to a reputable expertization service to either verify your findings or to obtain the answer that you could not determine. BlankPage