1 Mead Security Envelopes 6-3/4 80 Count #75030 3 5/8″ x 6 1/2″ Press-it Seal-It Mead 6-3/4 Security Envelopes Keep sensitive information confidential. Keep prying eyes off of your important documents with this number 6-3/4 security envelope. It has a printed lining for privacy, so it’s ideal for sending confidential mail, and the V-flap is fully gummed for a secure seal. Each envelope is constructed from 20-lb. bond paper. The 6-3/4-inch style and size is best for checks and brief notes