Each piece comes with a signed and hologram validated COA (Certificate of Authenticity) from ScreenUsed that states the following. This is one of the envelopes that were flying through the air in Harry's house. The envelope has a printed seal on the back in order to keep the prop envelopes light so they would fly around the room. Only a couple of close up letters had the real wax stamp on the back.
The version we have for sale is the "stunt" version. There were two types of envelopes used in filming. "Hero" close-up, handwritten envelopes, with enclosed letters, and actual wax seals were used when Daniel Radcliffe was interacting with the prop.
The "Stunt" version was made in larger quantities and were "printed" with no letter enclosed so the prop was kept lightweight for the scene when the envelopes were blasting out of the fire-place. While made in greater quantities, each envelope is still individual because of the random "veining" throughout the envelope. The Hogwarts coat of arms at back is a "printed" wax seal, to keep it light-weight. Here is a link to see the prop invitations in the movie. The item "Harry Potter (2001) Hogwarts Invitation Envelope (Screen Used) Stunt Movie Prop" is in sale since Thursday, August 15, 2019.
This item is in the category "Entertainment Memorabilia\Movie Memorabilia\Props\Originals". The seller is "collectionturkey" and is located in Los Angeles, CA. This item can be shipped worldwide.