Versatile Functionality—Every business has different needs, so these envelopes are sized to hold a variety of items, such as books, packets, slips, photos and more. Preprinted with a labeling system, which comes in handy for tasks with frequent back and forth. Secure string and button closure prevents papers from falling out and is reusable, with no adhesive for easy open and close. While the brown paper blocks anyone from seeing through, the durable open-end kraft construction ensures long-lasting use.