Folded bags with window combine the security of durable paper with very good product display resulting from the use of transparent PP film. Windows in bags can be made of PP foil without perforation, and of PP foil with micro perforation. Perforation in the form of small holes allows heat and steam to be removed from the packaged products. The windows in the bags may be centrally located or shifted to one side of the bag, alternatively they may have a panoramic form, covering one of the side folds and part of the front of the bag. Bags with windows are especially useful when packing all kinds of sandwiches and other multi-component products.