Biaxially oriented polypropylene slip film for packaging with stable coefficient of friction properties

A two-layer laminate film, comprising:

• a) a first resin layer comprising a polyolefin resin and having a surface treated by a discharge treatment method that imparts printability to the treated surface;
• and
• b) a second resin layer comprising a resin, a first additive material and a second additive material, wherein the resin of the second resin layer consists essentially of polypropylene and the second resin layer is formed on and adhered to a surface of said first resin layer opposite the treated surface having said surface treatment,
• wherein the first resin layer and the second resin layer each contain up to 800 ppm fatty amides comprising stearamide or erucamide,
• the first additive material comprises at least one crosslinked silicone polymer in an amount of about 0. 1% -0.5% by weight of the second resin layer and/or at least one silicone oil in an amount of about 0.02% -0.08% by weight of the second resin layer, and the second additive material comprises at least one amorphous aluminosilicate in an amount of about 0.10-0.50% by weight of the second resin layer.