The Traditional Tattoo or coil Machines are the most powerful, the needles perform a reciprocal movement, much like that of a sewing machine and they put in the greatest amount of pigment per second but because of this power, they also have the greatest potential for causing problems. With rotary or digital machines, the needles perform a forward and backward motion with a buzzing noise. The method I use is The SofTap hand method which is a gentle flick on top of the skin which is definitely the gentlest and virtually painless method There is no loud or buzzing noises, no moving parts that need to be tuned, adjusted or break down and there is no worry about sterilization, everything is single use only and disposed of safely.