The invention relates to a white, biaxially oriented film which comprises a crystallizable thermoplastic as main componet and is characterized by further comprising at least one UV-stabilizer, at least one white pigment and at least one flame-proofing agent, which is soluble in the thermoplastic and introduced directly, during the film production, by masterbatch technology, whereby the masterbatch is pre-conditioned by gradual heating under reduced pressure and with stirring.