With security tints & dependable adhesive, Quality Park Redi-Strip Security Envelopes are reliable as it gets for confidential mailing. Once priority documents are ready for shipping, be sure to preserve their integrity & condition inside the durable white wove paper. As you peel away the attachment & seal the envelopes closed, rest assured they'll be safe from prying eyes thanks to the security tint. Heat-Resistant Adhesive. Seam Type: Diagonal; Flap Type: Commercial; Trade Size: #10; Security Tinted: Yes.