office deed 500 #10 self seal double window security envelopes-designed for business statements, quickbooks invoices, and return envelopes 4 1/8 x 9 1⁄2’’ office deed office deed #10 double window security self seal 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 designed to protect confidential client information with our security tinted envelopes. 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 gummed flap provides for quick and easy sealing. the box contains 500 individual white business envelopes.