A method for producing an interior trim part in a vehicle having a decorative layer of leather, wherein the fiber structure of the leather is fixed by undercooling or by a fixing agent at least along a desired weakened line before the weakened line is produced by a laser and for the duration of the laser treatment. The leather comprises a dermis having an underside and a top skin having a decorative side. The weakened line is preferably formed by a series of perforations.