I was preparing to write a blog post on imperforate stamps when I stumbled upon a site where I learned that an error version of the stamps in the first day cover shown above existed. I was surprised to discover that I had a copy of the error. Can you spot the error below?
(Click on the picture to see a higher resolution version of the image.)
According to this website, this set of stamps has Scott number 1975 and the error version (1938 instead of 1988) has Scott number 1975e, with the price of the error version almost five times the price of the standard version. A slightly different version of my first day cover (with the error on the upper left—the same as mine—but with a different postmark) is currently being sold on a different website for 7.50 euros.
I just learned that (according to the Stamps on Stamps Collectors Club), there are three types of stamps on stamps: type A has a reproduction of the original stamp on the new stamp (such as the stamps I blogged about here and here); type B uses the original design with modifications; and type U has a reproduction of a stamp in an unidentifiable form. My two stamp errors so far (the one in this blog post and possibly this one) are type U.