Flat needles are needles that are soldered in a straight line to a needle bar. These needles are the most popular for lining because their shape lets them deliver more ink to the skin. This means clearer, darker lines with just one stroke. Larger flat needles can be used for color fills and deliver more quickly with just one pass.
Flat needles are marked FL (Flat Liner) or, less often, FS (Flat Shader) for short. Just like round needles, these are written out with the number of pins in front, like 7FL or 5FS.
Also like round needles, flat needles use their twin-sized tubes, so a 7FL needle will use a 7F tube.
