Need to send invoices, receipts, shipping manifests and other important documents with your parcels? Choose this pack of 1,000 Self-Adhesive Document Envelopes for dependable document attachment. Just pop your forms in and use the self-adhesive backing to stick it to a parcel or box, so your recipient can quickly access relevant documents. They're made of strong biodegradable film that's also waterproof to keep contents safe in all weathers. These A7 envelopes are supplied with plain exteriors.