These 5.75 x 8.75 white wove envelopes are well manufactured and a very good product for mailing cards in a Covid19 virus world. They do not need to be moistened (licked) yet the flap stays secured during the mailing process. As a journeyman envelope machine adjuster who has made billions of envelopes I see one major disadvantage to the self stick. The gum used on the flap may be environmentally unsound. I wonder what effect the gum has when the paper is recycled and returned to pulp. A "you lick it" adhesive will mix right in but I'm not so sure about the self-stick.