So now you've written your letter and are about ready to send it on its merry way... You don't really find examples of envelopes from the period, people would fold the paper up that their letter was written on and MAKE a little envelope.
How in the world do you do that? I'm glad you asked!
I was rooting around in an attempt to find some resources and stumbled across the following tutorials. Some are easy, some are more difficult.
PLUS a video that shows a fairly common folding method...