Our inter office envelopes with string 9x12 have hole punches on both sides allow recipient and sender to verify contents for your internal mail. Easy route envelopes within office - our intercompany envelopes easily support routing inter department mail with pre-printed lines to add name and department for recipient Our interoffice mail envelopes offer convenient string-and-button closure for easy access Maximized space with 5 columns and narrow ruling on with our inner office envelope 9 x 12 These 9"x12" interoffice envelopes are built with sturdy 28 lb. paper stock, ensuring durability and reliability in containing documents. The punched holes on both sides allow for quick content verification without the need to open the envelope, streamlining office workflows. Utilizing five columns maximizes space, facilitating clear and organized signatures for interdepartmental communication. The string-and-button closure provides both convenient access and secure sealing, maintaining document integrity during transit. Packaged in sets of 100, these envelopes offer excellent value, reducing the need for frequent restocking and ensuring a consistent supply for office use.