Abstract: Described is a process for the patterned metallisation of structured printed circuit boards in which the fully structured printed circuit board is covered with a solder stop mask, with the solder contact locations being left open, the solder stop mask is heated under such conditions that complete hardening does not yet occur and the copper surface of the printed circuit board is practically not oxidized, metal is deposited out of an aqueous bath at the exposed solder contact locations and after the metal deposit operation the mask is heated sufficiently long to a sufficiently high temperature that the mask is completely hardened throughout. The incomplete pre-hardening step prevents the solution infiltrating under the mask in the metallisation operation and thereby loosening the adhesion thereof.