Abstract: A manufacturing process for composite film for thermoformed products, including the steps of manufacturing a first plastic substrate film in the amorphous state, by extrusion, causing said first plastic substrate film to undergo a decoration/metal-finish process, causing said first plastic substrate film, to undergo a lamination step, characterized in that before said lamination step, on said first amorphous substrate film a layer of molten plastic material is laid, corning out of an extrusion head, and in that said first plastic film coupled with the layer of molten plastic material, immediately downstream of said extrusion head pass between an entry cylinder and a master cylinder of a lamination unit furthermore comprising at least an exit cylinder, the thickness of said first substrate film being in the range of 150-800? and the thickness of said molten layer being in the range of 150-1200? after lamination, said entry cylinder, master cylinder and exit cylinder being heat adjusted on temperatures in the r