did you ever have a present to give that fit into an envelope? and that wasn’t as pretty as the gift inside? i had this issue yesterday and decided the 2 envelopes should get dressed up a little bit. so i ended up using 2 different kinds of scraps to sew envelopes for the envelopes.
take a rectangular piece of fabric that is a bit wider and longer than the envelope. sew it close on both sides. turn inside out.
one envelope is for an awesome guy and i took a piece of an old hugo boss coat and closed the envelope with a button. the other one is for a lovely lady so i sewed to very long strings of silk ribbon onto the side of the sleeve and wrapped them all around the envelope to close.