Stamps (Philately)/1st Issue revenue stamp 3ct Prop. (Blue?)
I saw a 3cent blue proprietary stamp for sale. I have seen a blue one before. Just wondering if such a specimen exits or could it have been digitally retouched?
Thanks for the question,
Armand, although I can't be certain without actually seeing your stamp. Chances are that it is what some collectors refer to, as a color changling. These are stamps that were issued as one color and for various reasons (some to be explained later) has changed to another color. Although I have seen this on some mint stamps it is much more common on used stamps. I general these can occur for 3 main reasons.
1) Improper storage, the ink reacting to the paper/plastic used in storing it or even the air in some environment. You see this a lot with orange stamps that have turned either partially or completely brownish.
2) Another reason is over exposure to light/sun, this has a tendency over time to fade some colors such as red and yellow.
3) The last reason is it can be altered on purpose, using either chemicals or reason #2. This is why you see this a lot more on used copies, as once it is chemically altered it ruins the gum, and it would have to be regummed which is easier to detect.
Again, I am only speculating, but your stamp most likely has the yellow removed, (yellow and blue make green) so without the yellow it leaves just the blue.
I have attached a scan of a pair of 3c Washington that was chemically altered from purple to red.
Thanks again for the question,
I hope this helps