There are two ways to achieve a grey tattoo: use a grey ink or use shading techniques. A tattoo made using grey ink produces an even colour. The tattoo may feature a black outline and a one-shade grey interior. A tattoo made using shading techniques appears to have more depth and direction. If you are unfamiliar with the difference between tattoo shading and line work, you should not attempt to tune a tattoo gun. Tattooing is a very complex art that typically requires a long apprenticeship.
Adjust the armature bar. The armature bar sits at the top of the tattoo machine. The space between the bottom of the armature bar and the rest of the machine is known as a "point gap."
Tune the machine for line work. Place a dime under the armature bar. Turn the screws counter-clockwise to loosen them. Push the point gap until the top brushes the dime. Tighten the screws. To tune the machine for shading, use a nickel instead of a dime.
Attach the power cord of the tattoo machine to an electrical socket.
Adjust the voltage, if possible. For black or grey line work, the voltage should be slightly lower than for grey shading.
Adjust the tattoo gun's springs. Press down on the springs to increase the depth of the gun. Pull up on the springs to decrease the depth of the machine. A larger depth is appropriate for line work while a shorter depth is appropriate for shading.
Never attempt to tattoo someone without training under an accomplished tattoo artist.