Abstract: The inventive method relates to manufacturing of thermoformed packaging items or parts thereof having a non-uniform wall thickness and containing at least one layer with a specific function which at least one layer needs for this function a specific minimum thickness. In a first method step a multilayer film material (10) containing the layer with the specific function is produced, e.g. by coextrusion. In a second method step a thermoformable blank (30) is produced by injection molding onto the multilayer film material (10) a substantially flat injection molded part (21) with thicker and thinner portions. In a third method step the blank (30) is thermoformed into the packaging item or part thereof or into an item (40) from which the packaging item (50) is produced in further steps.