Hook envelopes are made from long fibers made of kraft paper; envelopes tongue painted green saliva glue (humidification can be sticky); hook is applied rust tough metal hooks, automatic riveting made; saliva plastic and iron double hook closure to prevent items are free to open a safe play lasting effect; reusable metal clasp hooks envelopes; 100% recycled paper envelope size range: minimum 70mm * 100mm; maximum 300mm * 460mm according to the customer's customized sizes, colors selected by the customer hooks; applies to files stored photo books, articles delivered packaging, important items collection?