<p>The biaxially oriented polypropylene monofilm is made from pure polypropylene and has an ash content of less than 50 ppm. The surfaces of the two sides of the polypropylene monofilm have different roughnesses Rz. The smoother of the two surfaces of the polypropylene monofilm is substantially free from fibrils and pits, so that metallisation of this surface is not accompanied by any flaws or defects in the metal coating to be applied.</p>
