Quality control is easy with the close-it® control seal. In contrast to normal labels, close-it® adheres well to sacks that are coated with powder (plaster, flour, etc.). Close-it® is a self-adhesive seal, with aluminum backing, which adheres very firmly. Sacks, cartons, etc. which have been pierced and sampled by powder-proof can be hermetically re-sealed with close-it®. The seal can be labelled wieth pen, pencil or felt-tip pen.