Use of stretched foil having at least two layers as a window foil for envelopes

摘要

In the present invention there is disclosed the use of a stretched foil having at least two layers, consisting predominantly of polypropylene and having at least one surface of reduced reflectance and which have been subjected to corona discharge, flame or fluorine for windows of envelopes. The foil exhibits excellent adhesive property, its surface brightness is less than 60 brightness units and is opacity is less than 40 percent.