PMU Cartridge & Needle Guide 2026: M1, Round Liner, Shader — What Every Configuration Actually Does

The PMU cartridge code, decoded

Every PMU cartridge is labelled with three pieces of information:

Example: 1003RL-T (12ga)

• 10 = needle diameter in tenths of a mm → 0.30 mm (a "10" gauge, also called "10 bugpin" or "12 standard")
• 03 = number of needles in the grouping → 3 needles
• RL = configuration → Round Liner
• -T = taper length → Long Taper (softer stroke)
• 12ga = the wire gauge — 12 is standard PMU; some brands sell 10ga (bugpin, finer)

Once you can read the code, every brand's cartridge line becomes shoppable.

The five configurations that cover 95 % of PMU work

Code	Name	What it does	Use for
RL	Round Liner	Tight cluster in a circle	Hair strokes, eyeliner, hairline SMP
RS	Round Shader	Loose cluster in a circle	Small-area shading, nostril fill
M1 / MG	Magnum	Flat rectangular cluster	Wide shading, ombré brow gradient
CM / SEM	Curved Magnum	Curved cluster that follows skin contour	Lip blush, eyeliner base shading
1RL / 1PT	Single Point	One needle	SMP dots, hairline detail, colour correction

If you own five cartridge configurations (1RL, 3RL, 5RL, 5M1, 7M1) you can service every brow, lip, eyeliner and basic SMP session.

What is a "PMU cartridge M1"?

M1 is the flat magnum configuration — needles arranged in a single straight line perpendicular to the cartridge body. It is the standard shading cartridge for PMU: powder brows, ombré gradient, lip blush base saturation.

A 5M1 puts 5 needles in a flat row (about 1.2 mm wide). A 7M1 puts 7 (about 1.6 mm). Bigger magnums cover more skin per stroke but need more pigment saturation to avoid patchiness.

Round Liner vs Round Shader

Both are round clusters — the difference is how tightly the needles are packed.

• Round Liner (RL): needles fused tight at the tip → prints a crisp line. Use for hair strokes, eyeliner, single-line work.
• Round Shader (RS): needles fanned slightly apart at the tip → prints a soft dot. Use for small-area shading where a magnum is too wide.

On oily skin, prefer the tighter RL — a fanned RS bleeds pigment on high-sebum brow bones.

When 12-gauge matters (and when it doesn't)

12-gauge is standard PMU wire (about 0.35 mm). 10-gauge (also called "bugpin", about 0.30 mm) is finer and creates crisper hair strokes on dry, thin skin.

Skin type	Recommended gauge
Dry, fair, mature	10-gauge (bugpin)
Combination, most Asian tones	12-gauge
Oily, thick, sebaceous	12-gauge or thicker

10-gauge on oily skin over-implants and heals blurred. Match the wire to the skin, not to a brand's marketing.

Single-needle work (1RL / 1PT)

A single-needle cartridge — one needle, no cluster — is the newest configuration in professional PMU. It is used for:

• SMP hairline detail (individual follicle-mimicking dots)
• Nano-brow hair strokes (the finest, most natural stroke possible)
• Colour correction over healed work (target one small area without touching the surrounding pigment)

Single-needle work is slower and less forgiving of hand-drift; it belongs in the toolkit of an experienced artist, not a first-year one.

Universal cartridge fit — why it matters

A PMU machine that fits only its own manufacturer's cartridges will cost you 2–3× per session in consumables. The industry standard is a universal cartridge fit (the same standard used by Cheyenne, FK Irons, and most rotary machines).

FNS machines are universal-fit — you can load Cheyenne, Kwadron, Bishop, Mast, or Vertix cartridges interchangeably. Cartridge cost per session drops from ~$3 (proprietary) to ~$1.

Cartridge shelf life and storage

• Sealed cartridges: 5 years from the sterilization date printed on the pouch.
• Once the pouch is opened: use within 24 hours or discard.
• Store at room temperature, away from direct sunlight and humidity.
• Never re-sterilize a cartridge. Every cartridge is single-use, single-client.