In 1992, the US released a series of 6 mini souvenir sheets reprinting the 1892 Columbian stamps.
The sheetlets came in a small envelope with a cardboard insert.
I purchased one, removed the sheets and mounted them in my album.
I have no need for the envelope and insert, but I know that some people keep them and/or there is a slight premium for a set in the envelope.
SO... if you want the envelope, let me know -- it's free to a good home.
Just to be clear, no stamps are included; just the wrapper