#10 Business-sized / standard envelopes (4 1/8 X 9 ½ inches) is ideal for offices such as billings, invitations, business mailings, greeting cards, contracts and other letter invites. It is designed to hold a standard 8 ½ x 11 inch piece of paper or letter size. The envelopes are made from 24 lb. bond (60 Text) bright color paper stock (90 gsm), which works perfectly on a wide array of digital equipment and usage.