A  tattoo machine is a hand-held device which helps to create or design a tattoo. Tattoo machine is a gun-shaped machine that permanently marks skin with ink. Modern tattoo machines use alternating electromagnetic coils to move a needle bar up and down, driving pigment into the skin. The word "machine" or "iron" are generally used by the tattoo artists, for the equipment which helps in making tattoo. The word "gun" is often used by people who are not well-informed about the tattoo industry.

Origin Of Tattoo Machine- Stencil-Pens
You would be surprised to know that Thomas Edison, who invented the electric bulb, is responsible for inventing the first tattoo machine prototype. Edison invented a battery powered device called "Stencil-Pens" in 1876. This Stencil-Pen punches holes in paper, forming different designs and patterns. The colored powder was dusted over this punched paper to transfer the pattern onto the object. This technique to form designs on paper was transformed and was used to make designs on the skin. Samuel O'Reilly modified the Stencil-Pens after fifteen years.

Other Inventors Of Tattoo Machine
In his new design, Samuel included an improved tube assembly, an ink chamber and a needle to insert ink into the skin with on and off switch and stroke adjustment capabilities. Thus, after registering his design, O'Reilly received the first tattoo machine patent. In 1929, Percy Waters patented the new design which closely resembles the modern day tattoo machine. In this new design, two electromagnetic coils were used to set parallel with the frame, including a spark shield and an easy on and off switch. After fifty years, in 1979, the next design was issued to Carol "Smokey" Nightingale. His design had springs of different lengths for detail work and a lever for the adjustability of the coils.

Modern Tattoo Machines
Modern tattoo machines are good enough to control the speed of the needle, its depth, and pressure. The machines are so efficient that a particular type of facial tattooing, such as, derma pigmentation or permanent makeup, is also safe with these machines. Generally standard machines are used by all tattoo artists, but they modify them according to their tattoo styles and techniques. As the tattoo artists don't bother to register their modifications, the new designs are not able to identify. Thus, Tattoo machines will keep on improving in design and application with constant research of tattoo artists, for the perfect tattoo machine.

Working Of Needles In Tattoo Machines
There are two types of needles found in a tattoo machine: One for shading and another for lining. The number and type of needles needed is based on the decision of tattoo artist according to the preference of the customer. The needles are pushed in and out of the skin from 100 to 3,000 times per minute. When the needle moves upward near the tube, it enables the needle to get the ink. The second layer of the skin called "dermis" is the primary target of the needle to inject the ink.