There are many different types of machines. Liners and shaders are the two most common machines from a technical viewpoint. Mechanically, there are coil tattoo machines; pneumatic machines, and rotary tattoo machines.
The most commonly used tattoo machine is the two coil tattoo machine
These can be found for purchase at any good tattoo supplies website
Although if you are just getting started one might suggest that you get a rotary machine to begin with as they are much easier to set-up and use as a beginnner. The best rotary machine you will get for your money is the Red Devil Rotary Tattoo Machine for around $140 you can get your hands on this awesome piece of equipment. This rotary machine is very versatile, silent and smooth, it fits regular tips, grips and needles and can be used for both lining and shading.
If you are looking to buy a machine online but are not sure where to start, I suggest visiting bstattoo.blogspot.com for more info on which machine would be most suitable for you. Big Slick Tattoo supply sell high quality tattoo supplies at the cheapest prices around, be sure to check them out.
• Rotary tattoo machine: A rotary tattoo machine, built 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.
• 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 ohms,or resistance, used to properly regulate the machines speed and power. Causing less trauma to the skin.
• 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 1.5mm–2mm), which causes the machine to cycle faster.
• Shader tattoo machine: The shader machine is commonly used to shade black or variants of black ink. Also Color is 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–3.5mm) 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.
• Pneumatic tattoo machine: Tattoo artist Carson Hill in the year 2000 invented the first pneumatic tattoo machine and began the patent process. A pneumatic tattoo machine is powered by an air compressor, and they are extremely lightweight. Pneumatic tattoo machines use pressurized air to power the tattoo machine and drive the needles up and down. These tattoo machines are entirely autoclavable, so that the entire tattoo machine can be placed in the autoclave and sterilized fully without any major disassembly. Unlike traditional coil machines, which require complete disassembly to be placed into an autoclave.
Tattoo machines are not limited to just these types. A common variant is having a "cutback", which uses stiffer front springs. This is more commonly used in liners, but is known to be used on shader machines, more typically for portrait work. Machines are usually categorized into long stroke and short stroke varieties. The longer-stroked machines are good for coloring and shading, as well as sculpting lines, while doing less damage to clients' skin. Shorter-stroke machines are commonly used for lining in a single pass style, and also in a shader setup to achieve a more subtle gradation of black such as would be found in portraits. Length, width, tension, angle, and stiffness of the spring varies the functionality of the machine. The contact gaps, as well as capacitor's and even the style of machine and its angles of deflection, can also all be variants in machine tuning. The proper tuning of the machine is essential for the type of machine being used, also for the type of tattoo the artist is doing.