If you run a mail order or online selling business and are looking for postal supplies these postsafe envelopes are ideal 335x430mm c3 in size they are perfect for larger items and being so lightweight they help to keep postage costs in check and despite being made from such a light polythene material they are immensely strong made in the uk these biodegradable peel amp seal envelopes are made in the uk by postsafe postsafe have carved out an excellent reputation