Strathmore Writing Envelopes, 10 Commercial Flap Writing 25% Cotton Wove Finish 24 lb, 4-1/8 x 9-1/2 Inch, 500 Envelopes/Box - Sold as 1 Box, Ivory (M45831) 25% Cotton #10 Commercial Flap Envelopes (4-1/8 x 9-1/2 Inch) 500 envelopes per box 24lb (90 gsm) Wove Finish Matching paper stock available Inkjet & Laser Compatible. Acid Free for Archival purposes