Product Information: Manufactured from Printed Polythene, Internal Dimensions 318mm (width) x 225mm (height). A4 Document Size. Strong Adhesive Backing. Packaging Shack’s range of Documents Enclosed Labels are designed to attach invoices, dispatch notices etc. onto packages and cartons. Manufactured from strong Polythene and featuring a peel able backing with strong adhesive that ensures that any enclosed documents remain with the attached package through the postal system and are protected from dirt, dust and moisture.