Stamp collectors are resourceful. Glassine envelopes are great for storage for duplicates. This creates confusion later on for family members who are trying to sell a loved one’s collection.

A glassine will be stamped, for example, “Russia #24. $125”. However, that Russian stamp is long gone into a stamp album. What’s inside now are three damaged copies of US Scott #65.

The seller has no philatelic knowledge. All they know is what is stamped on the glassine. Thinking that Grandpa Joe must have spent $125 on this stamp. And now there are 3 of them in this envelope. That’s $375!

When I review the collection, my offer comes to, say, $100. Wait a minute! According to the glassine envelopes, there are over $5000 in stamps here! Now the seller thinks that I’m some crook.

I never trust any markings with value or catalog number. Sometimes they are correct. Many times, they are wrong.

As a seller, if you see markings of value and catalog numbers, just realize that this could be a reused envelope and the contents inside may not represent what is written on the glassine.