These Reusable Envelopes are the perfect solution for holding, protecting and organizing letter-sized papers and documents. They are made of strong biodegradable polypropylene and close securely with a hook and loop closure to hold documents firmly inside. In addition, the closure makes it possible for Reusable Envelopes to be used time and time again, making them cost-effective. The contents are clearly visible for quick reference or may be inserted backwards with a routing sheet for privacy. C-Line Reusable Envelopes are perfect for important document storage and transporting inter-office correspondence. Made by C-Line Products, a leading manufacturer of office supplies for home, school and business. C-Line produces products for storage, identification, organization and protection.