Brown Kraft Roptex coin envelopes size 3-3/8 x 6". These envelopes are ideal for small parts, samples seeds, loose coins and payroll applications. These envelopes also work well as crime scene evidence collection envelopes. Flaps feature deep gumming for a secure seal. No. 6G coin envelopes are made of sturdy, 28 lb. Kraft stock. Packed 500 per box, 10 boxes per case.