Office Deed #10 Double window security envelopes are designed for convenience, reliability and security. These are made from high-quality 24-lb white wove. Wove finish adds a professional touch. Envelopes #10 designed to Protect confidential client information with security tint print. The blue tint pattern makes impossible to see the details of the contents, even when held up to the light. Mail invoices, statements and other important documents with confidence. The woven finish gives them a neat appearance and professional appearance. The self seal design flap provides for quick and easy sealing. The box contains 500 individual white business envelopes.