With security tints and 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 and condition inside the durable white wove paper. As you peel away the attachment and seal the envelopes closed, rest assured they'll be safe from prying eyes thanks to the security tint. Address Window & Heat-Resistant Adhesive. Seam Type: Diagonal; Flap Type: Commercial; Trade Size: #10; Security Tinted: Yes.