The needle of a tattoo machine punctures the skin 50 to 3,000 times per minute. Tattoo artists have control of the tattoo machine and can set it to run faster or slower depending on how comfortable they are with the machine.
The skin of the person being tattooed also plays a part in how fast the artist sets the tattoo machine to run. Fleshier parts of the body require more ink, so the artist may speed up the needle. More mature skin is thinner, so a slower needle helps avoid tearing delicate skin. In addition to speed, the tattoo artist can control how deep the needle penetrates the skin.