Business envelopes are just as important as the materials contained inside. Equip your business for success with a wide range of styles and sizes of business envelopes. Find Square Flap Envelopes for invitations, Window Envelopes for checks, Booklet or Open End envelopes for larger mailings, and Expansion Envelopes for books or large stacks of paper. Our envelopes come in many sizes, colors, and styles, and many of them can be custom printed with your business logo, return address, and more!