Quality Park Postage Saving Envelopes, 28 lb, 6 x 9.5 Inches, White Wove, Box of 100 (90064) 6 x 9.5 Inch size qualifies for USPS letter rate Go from flat to a half fold with your documents and save money on postage 28 lb. paper specifically designed to perform while holding extra copies and weight. Features a deeper gumming for improved seal