<Li> Rotary tattoo machine: A exenter - rotary tattoo machine, invented in 1978 by Manfred Kohrs of Germany . Rotary tattoo machines were the original machines, based on rotary technology, which was invented by Samuel O'Reilly and improved by the tattoo artists through the years . Rotary type machines use an electric motor to drive the needles . Some recent upgrades include using an armature bar to increase efficiency, a characteristic of coil machines . Recently, there have been improvements to make this type of machine pneumatic, in place of the electric motor used now . </Li> <Li> Coil tattoo machine: Coil tattoo machines are the most commonly seen and used . These machines use an electromagnetic circuit to move the needle grouping . There are many variations, from single - coiled machines to triple - coiled machines . They can be made from many different materials and in many different sizes and shapes . Dual - coiled machines are considered to be standard . The coils generally range from 8 to 10 wrap . The coils create the impedance, or resistance, used to properly regulate the machine's speed and power . This causes less trauma to the skin . </Li> <Li> Liner tattoo machine: The purpose of a liner machine is to lay the ink in the skin in one single pass to create a dominant line . It uses a short contact circuit (about 1.5 mm--2mm), which causes the machine to cycle faster . </Li> <Li> Shader tattoo machine: The shader machine is commonly used to shade black or variants of black ink . Also colors other than black are used in this type of machine . The saturation level of this machine is low . It uses a bigger contact gap than a liner (about 2mm--3.5 mm) to make it cycle slightly slower . This machine is also used for sculpting lines . Some artists will use this type of machine for all lines, as it allows the lines to be retraced with less trauma to the skin . </Li>

How many tattoo needles are in a gun