1 - Lacquer Mastering: the contents of the “master tape”, word that defined the backing on tape in which the artist had taped all his songs, was transferred by a process called “lacquer-cutting” and by a specific instrumentation (namely the “cutting-lathe”), through which it is possible to work on a level of equalization and compression, on a disc called “lacquer”: it is an audio container which looks very similar to any normal record as you can find in shops, but in reality it is made by a lacquer-coated aluminum disc. The lacquer, once it has been cut, is put in baths and electroplated with nickel; this coating, once removed from the lacquer itself, reproduces a metal “plate” (that has some “bumps” instead of the usual grooves), or as to say the two matrices (whose technical name is “fathers”) which are electroplated again giving so origin to the mother plate that generates, as consequence of a further plating process, the stampers.
2 - DMM (Direct Metal Mastering): unlike conventional disc mastering, where the mechanical audio modulation is cut onto a lacquer-coated aluminum disc, DMM cuts straight into metal (copper), utilizing a high frequency carrier system and specialized diamond styli, vibrating at more than 40 kHz (i.e. 60 kHz) to facilitate the cutting. The DMM copper master disc can be plated to produce the required number of stampers using the one-step plating process. Rather than having to electroform a master (or "father"), mother and then stampers (the traditional "three-step process"), the DMM copper disc serves as the 'mother". Bypassing the silvering process and two electroforming stages reduces the risk of introducing noise that can be generated in the electroforming (galvanic) process. In cases where hundreds of stampers may be required, the DMM disc is often plated to produce a master and mother, from which many stampers are then made.
The following is more information help us to make decision..
DMM (Direct Metal Mastering) became popular during the 80’s but was soon less favourable as more cutting engineers went back to lacquer. It was co-developed by Neumann and Teldec, and instead of engraving the groove into a soft metal lacquer-coated aluminum disc, a DMM lathe engraves the audio signal directly onto a hard metal copper-plated master disc.
The difference between a DMM cut and a lacquer cut is that the DMM is more precise, with sharper transients and better image “edge definition,” while the lacquer cut is smoother, warmer and more pleasing on the ears.
DMM (Direct Metal Mastering) cuts always appeared to have a brighter and more defined top-end. Upon early inspection of DMM discs, this appeared to be due to a higher frequency modulation in the groove, caused by an ultra-sonic carrier tone. However there is no carrier tone on DMM cuts and the modulation is simply caused by the vibration of the cutter head.
Many critics often describe a DMM cut as too bright or too ‘edgy’. Often the reason for playing a vinyl record is to have the warm and analogue sound that is often not present in a DMM cut.
DMM did though eliminate the problem of pre-echo sometimes audible on a lacquer. Pre-echo is caused by the cutting stylus unintentionally transferring some of audio signal into the previous groove wall, causing a faint audio signal, a pre-echo.
Another argument for the use of DMM is that it removes the need for one stage of the galvanic process. Since the DMM (Direct Metal Mastering) is cut onto copper the first stage of electroplating is bypassed, resulting in cleaner processing with less surface noise and less chance of error during processing.
Although the warmer sound of lacquer could arguably be put down to the cuts not sounding as bright as DMM, the fuller sound of lacquer could be credited to the depth of the grooves on a lacquer. Lacquers can be cut much much deeper than DMM which is essential for music with a prominent low-end signal. As well as giving the fuller sound, a deeper groove is needed to avoid jumps and skips on a turntable. And even though DMM has much brighter more defined frequency response in the top end, this certainly isn’t the case with the bass frequencies, evident in most of today’s electronic music. ( Article from WTadmin pressingvinyl uk )