Quality Park Clasp Envelopes, 10 x 13 inches, (QUA37797) Go to amazon.com Related posts The 7 best 10x13 clasp envelopes for 2022 FeatureReinforced clasp design100 / BoxSize: No. 97 (10" x 13") DescriptionRugged envelopes feature reinforced clasp design and deep gumming on flaps for secure seal. Envelopes are made of extra heavy-duty, 32 lb. Kraft stock.