Brown Kraft String & Button Interoffice Envelope, #90, One-sided Five-column Format, 9 X 12, Brown Kraft, 100-cartonWhether you're delivering documents between departments or transferring assets from one building to the next, Quality Park String & Button Inter Department Envelopes are an excellent choice to have on hand. Preprinted labeling allows you to record the date, time and other notes before passing materials off to someone else. 31 Entry Routing Table. Seam Type: Center; Flap Type: Cheese Blade; Trade Size: #90; Security Tinted: No.