10" x 13" interoffice envelopes have a bold personal and confidential message on all sides. Heavyweight, 28 lb. paper protects sensitive information. Heavily gummed closure keeps contents secure as your envelopes travel interoffice mail routes. Signature line across the flap records the sender's name. Just seal and sign to create a secure, tamper-evident package. Large box on the back records the name of the recipient, their location and department. Interdepartmental envelopes are a must in any office. Specialty envelopes make confidential documents obvious and recognizable to keep them on their intended course. Opaque construction provides privacy and is durable enough for any in-house mail system.