The JAM Paper #11 (4.5" x 10.375") envelope makes a great option for distributing official materials, sending mails or filing important papers.JAM Paper® Brown Kraft #11 Commercial Business Envelopes are made out of smooth, high quality, 28lb paper. This pack contains a total of 50 envelopes. Each one of these envelopes measures 4 1/2 x 10 3/8 inches in size. Featuring a basic and versatile brown craft color, these envelopes are ideal of a wide variety of personal and business mailing purposes! Their size makes them perfect for three-times-folded standard sized sheets of paper. Use them to send documents and letters from your home or office with ease! Each one features a commercial flap opening and a reliable gum closure to keep the items placed inside secure as they make their way through the mail.