Leather envelop for mailing a letter back and forth

[johnv474]

Rubber cement will hold as well as regular envelope's gummed seal.  if it needs more, have a few holes you can stitch through, like on a button.

Thin Velcro could also work. 

Be aware that postage will cost you m9te because leather envelopes are not made to be processed in postal facilities.

Also, don't be surprised if the envelope disappears after enough people see a leather envelope and decide they'd like one.  Use certified mail, put the whole thing into another envelope.