the invention relates to a process for producing a three - dimensional stiffening element from a powder selected from the group consisting of a meltable plastic powder and a powder mixture comprising the meltable plastic powder comprising applying the powder to an auxiliary carrier in a template screen printing process with the aid of a template and subsequently transferring the thus obtained stiffening element to a substrate , the improvement comprising subsequent to the step of applying to the auxiliary carrier , compressing and sintering the powder with a hot molding plug to obtain a blank ; lifting the plug while removing the blank from the auxiliary carrier and further melting the sintered plastic particles of the blank which are in contact with the molding plug ; and said step of transferring comprising transferring the further melted blank onto the substrate disposed therebelow while lowering the molding plug .