The initial micro-dot and micro-line patterns were first ink-jet printed onto the surface of polished AISI420 stainless steel mold. This masked mold substrate was nitrided at 693 K for 7.2 ks at 70 Pa by using the high density plasma nitriding system. The unmasked parts were selectively nitrided to have higher hardness than 1200 HV. This hardness profiled substrate was mechanically sand-blasted to fabricate the micro-textured mold. Micro-disc patterned plastic cover-case for cellular phones were injection-molded by using this method for practical demonstration. Both the selective hardening and anisotropic inner nitriding processes were experimentally discussed as a key step in the present processing.