19-10-2025, 07:53 PM
The stamp on the left has suffered environmental/chemical damage.
Soft vinyl products of the 1960s-70s used plasticizers that bleed oils over time and react with stamp inks. The result often appears similar to aniline ink bleed-through, and the oils soaked into the paper can solidify over time to give a waxy appearance -- exactly what you are seeing.
I have seen this so many times that I am looking for it whenever I buy collections that are housed in any of these kind of plasticized vinyl products.
It is usually associated with certain cover albums of the period, but other products like coin collecting vinyl pages intended to hold "2x2" cardboard coin holders are also culprits. I have seen many collections that used those to hold multiple copies of a collector's duplicates.
Roy
Soft vinyl products of the 1960s-70s used plasticizers that bleed oils over time and react with stamp inks. The result often appears similar to aniline ink bleed-through, and the oils soaked into the paper can solidify over time to give a waxy appearance -- exactly what you are seeing.
I have seen this so many times that I am looking for it whenever I buy collections that are housed in any of these kind of plasticized vinyl products.
It is usually associated with certain cover albums of the period, but other products like coin collecting vinyl pages intended to hold "2x2" cardboard coin holders are also culprits. I have seen many collections that used those to hold multiple copies of a collector's duplicates.
Roy
https://buckacover.com << 90,000 covers 60c to $1.50 !!!
https://discountstampshop.ca << Discount Stamp Shop - The name says it all!
"The next best thing to a stamp show"