"Milky" White Film Fronted Paper Bags have a clear polypropylene front and an acid-free bleached white paper backing. Window bags, duplex bags or sandwich bags, are primarily used in the catering and food industry to package and display sandwiches, filled rolls, bread, pastries and cakes. Also extensively used in the photographic and gift industries as an economical way of packaging and displaying mounted pictures, prints and cards. As they are film fronted, these bags ensure that the contents are protected but clearly seen.