A liner is a type of tattoo gun that should be used for the process of lining or applying the outline of ink to the skin. There are three types of tattoo machines: one that can provide both lining and shading and two that function separately. While the tattoo gun that can both shade and line may sound easier, it’s actually more difficult for beginners to use.

The liner will generally have fewer needles than a shading machine. This is so it can be used to work on finer details. Holding up to seven needles, the liner’s needles are arranged in a circle. Shading machines typically have needles that are arranged in a line, similar to a comb, and are heavier than liner machines.

The purpose of the liner machine is to create a dominant outline to set the tone for the rest of the tattoo. Typically, the liner is done by tracing a hand-drawn stencil that was transferred to the skin.