The envelopes are not as flexible as I would have hoped. The adhesive seems to be ok but do to its rigid manner the envelope rips when you place larger items in them.
Usable interior dimensions: 8.5 x 11 (flat). Exterior dimensions:9.5 x 11.25 (flat). Arrived in perfect condition - no wrinkles or creases. The peal-n-stick closure is seriously sticky - the flaps will not come undone in the mail!