Widely Use: The small kraft envelopes are 500pcs per box. Feature: These small brown envelopes are made from kraft paper, and this small envelopes size is about 2.25″ x 3.5″. Water Glue Seal: The mini envelopes are water glue seals, when you put the sorting and storing seeds, small electronic components, or other contents into the envelope, folding and keep the flap glued 3-5 minutes.