Complete newbie to stamps and the back of all the non self-adhesive stamps from 1980's and 1990's that I own are white in color and the gum is either white or invisible. I recently purchased two #2224 22c Statute of Liberty Centennial sheets described as being in Mint condition, but the back of the stamps have a yellowish tinge to them, kind of like what happens to the pages of non-archival photo albums as they age. Were some stamps issued with yellowish gum or is this the normal course of the stamp aging process? Can a stamp sheet still be considered mint condition with this yellowing? I have attached a photo illustrating the yellowing.
Posted 12/15/2018 02:49 am
