Mail documents you need to keep private in these No. 6 3/4 security envelopes with a lining to shield your information. Self-sealing, letter-size envelopes are perfect for general everyday mailing needs. Sized to hold letter-width correspondence, these envelopes have self-adhesive strips, so you can seal them easily, quickly and securely. No more moisteners, gummed flaps, tape, or glue. Just pull back the protective tape from the flap of each self-sealing letter-size envelope and close it down onto the 20-lb. envelope for a secure seal. Extra strong adhesive keeps documents protected. Address them by hand or use computer labels. Each envelope is constructed from 20-lb. bond paper. The 6-3/4-inch style and size is best for checks and brief notes.