O'Reilly - History of Tattoo Machines
O'Reilly invented the electric tattooing machine in 1891. O'Reilly
upon an earlier tattoo machine invented by Thomas
Edison that did not succeed commercially. Tattoo machines work by using
a hollow needle filled with permanent ink. An electric motor pushes the
needle in and out of the skin at a rate of up to 3,000 punctures per minute.
The tattoo needle inserts a small drop of ink about 1/8 of an inch below
the surface of the skin each time.