Tattoo needles: the differences between RL, RS, M1 and magnum
Cartridge boxes carry codes like 3RL, 7RS, 9M1 or 15RM. Understanding them is key to choosing the right needle for each part of a design. This guide explains the most common configurations and how they combine with gauge and taper.
How to read a needle code
The number tells you how many points are in the grouping. The letters describe the shape: RL (round liner), RS (round shader), M1 (flat magnum) and RM or CM (curved magnum). You will often also see the gauge, such as 10 (0.30 mm) or 12 (0.35 mm), and the taper, which describes how sharp each point is.
For example, 1003RL means gauge 10, three points, round liner. Reading the label carefully avoids surprises mid-practice.
RL: round liners for lines
Round liners pack the points into a tight circle to draw crisp lines with concentrated ink. Fine ones such as 1RL or 3RL handle detail; 5RL, 7RL or 9RL give bolder lines typical of traditional work.
A 3RL or 5RL is a great choice for line drills because it clearly shows shaky hands and uneven depth.
RS: round shaders for small fills
Round shaders are also circular but with more space between the points. They deposit ink more softly and suit small fills, shading in tight areas or lines with a softer finish.
They are useful where a magnum would be too big, such as inside lettering or small decorative elements.
M1: flat magnums
M1 needles arrange the points in two alternating rows forming a straight edge. They cover more area per pass and are used for solid colour packing and shading in medium or large areas. The straight edge can leave marks at the wrong angle, so they take practice.
Many artists use M1 for solid colour and keep curved magnums for gradients.
Curved magnums (RM or CM)
Curved or soft-edge magnums set the points in an arc. That arc follows the skin's curve and produces smoother shading with seamless transitions. It is the usual choice for black-and-grey gradients and realism.
With moderate voltage and a pendulum or whip motion, it lets you build tones gradually.
What to choose for practice
Start with a few references: a 3RL and a 7RL for lines, a 7RM or 9RM for shading and a small M1 for fills. Always use sterile single-use cartridges with a visible expiry date and dispose of them in a sharps container.
The beginner's manual and Necrographia cover needles, voltage and stroke in more depth as study material, without replacing training with a professional.