Coil machines are a type of tattoo machine that use electromagnetic coils to create the needle's movement. These machines operate by energizing coils, which pull a metal armature bar down, causing the needle to puncture the skin and deposit ink. Coil machines are known for their versatility and are often favored by traditional tattoo artists for their ability to produce a variety of line work and shading techniques. The design of coil machines typically includes a frame, coils, a power supply, and a needle assembly. Artists can adjust the machine's settings to control the speed and depth of the needle, allowing for precise tattooing. Many tattoo artists appreciate the tactile feedback and control that coil machines provide during the tattooing process.