Abstract: The invention is directed to a process for producing a outsole or inner sole of a footwear comprising the following steps (a) providing a first form negative mould of the outsole or inner sole comprising of at least one formed plastic sheet as obtained by thermoforming using a first master mould corresponding with the shape of a first side of the outsole or inner sole, (b) adding a liquid curable composition to the first form negative mould, and (c) solidifying the curable composition wherein a solidified outsole or inner sole is obtained and wherein the first form negative mould is removed from the solidified outsole or inner sole.