A master tool is provided with an ink pattern on a major surface thereof. The ink pattern is formed by a screen printing process. A stamp-making material is applied to the major surface of the master tool to form a stamp having a stamping pattern being negative to the ink pattern of the master tool. The stamping pattern is inked with an ink composition and contacted with a metalized surface to form a printed pattern on a metalized surface of a substrate according to the stamping pattern. Using the printed pattern as an etching mask, the metalized surface is etched to form electrically conductive traces on the substrate.
