Use interoffice envelopes with string-and-button closure for document routing. They are a must in any office. Envelopes keep documents contained and organized while routing throughout the office. 28 lb. Brown Kraft stock is durable for prolonged use. String-and-button closure holds up over time and is an easily accessible closure. Envelopes are formatted with three columns on each side with wide ruling for signatures. Holes allow visual acknowledgement of contents.