Direct Metal Mastering. With Direct Metal Mastering the groove is cut directly in copper metal. High-frequency loss, distortion and pre-echo associated with conventional lacquer mastering are eliminated and transient response is greatly improved. DMM record pressings sound brighter, cleaner, more detailed, and with 15% more playing time than with lacquer technology. Stampers are plated directly from the DMM Copper Master, eliminating two of the three plating steps required for lacquers. DMM yields better detail resolution and lower noise.