String & button interoffice envelopes can be used and reused for years. On Time Supplies features a nice selection of durable string & button interoffice envelopes from the top office supplies brands with bulk pricing discounts and GSA rates. Thanks to our lightening fast shipping, your interoffice envelope order arrives at your office just 1-2 days. Questions about interoffice envelopes, or any of the other discount office supplies for sale at On Time Supplies? Call us toll free at 1-866-501-6055. Our friendly customer service representatives are happy to answer any supply questions.