To obtain an opaque polyolefin film capable of setting translucence or opacity by a simple means and capable of changing the same within a wide range by adding particulate hollow bodies of an incompatible polymer to the vacuole-containing layer of a stretched film comprising a thermoplastic polymer.
The vacuole-containing layer of a film contains particulate hollow bodies consisting of a thermoplastic polymer, pref., polyolefin, especially, a propylene polymer and a polymer incompatible therewith and, if necessary, other additives. Generally, the vacuole-containing layer contains at least 60%, pref., 70-99% by wt. of the vacuole-containing layer of the thermoplastic polymer. The light permeability according to STM-D1003-77 of the film is below 95%, pref., 50-80%. By light permeability, translucence, opacity and/or white- opacity are discriminated.