Discussion in 'United States Stamps' started by RichardBabcock, Dec 30, 2020.
Issued May 6th,1968.
Lighter fluid and a bright light is one way. I tend not to remove stamp if I dont have to.
I have never tried to detect US watermarks from the frontside,let alone
on paper.They are difficult enough to spot them from the backside !
I never had a closer look to the above stamps.
Comparing the backgrounds,one might think they are quiet different.
Issued May 10th,1971
Issued May 10th,1971.
Separate names with a comma.