Hollow Round Liner Cartridges for Bold, Consistent Outlines

R&G Bio manufactures hollow round liner tattoo cartridges for distributors and brands supplying traditional and bold-line artists — an open needle structure with strong, steady ink delivery.

The hollow arrangement supports smooth flow and bold line work, making it a dependable choice for outlines that need both clarity and impact. The needle stays stable, ink feeds consistently, and the line moves cleanly through the skin.

Every cartridge is EO gas sterilized, batch-coded for full traceability, and produced in ISO Class 7 cleanrooms under an ISO 13485 quality system. Review our certifications and compliance documents and see how we manufacture before you place a bulk order.

We support full OEM/ODM programs — housing colors, private labeling and custom packaging built around your brand, with factory-direct MOQs and tiered wholesale pricing.

FDA Registered CE-RoHS ISO 13485 Sterile EO
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  • Open-Center Ink Flow
  • Bold Consistent Outlines
  • Stable Needle Seat
  • EO Sterilized
  • OEM/ODM Ready

Model Reference

1
For example – 1203RL

12 – Needle Diameter (Gauge)
03 – Needle Count
RL – Needle Configuration

2
Needle Diameter (Gauge)

12 = #12 (Standard, approx. 0.35 mm)

3
Needle Count

03 / 05 / 07 / 09 / 11 / 14

4
Needle Type

RL = Round Liner
RS = Round Shader
M1 = Magnum (Double Stack)
RM = Round Magnum
CM = Curved Magnum
F = Flat Shader
RLT = Textured Round Liner
TRL = Turbo Round Liner
STL = Super Tight Liner

#12 · 0.35MM — OPEN CENTER, HIGH INK FLOW

MODEL

GAUGE

TAPER

NEEDLE COUNT

MEMBRANE

STERILIZATION

FIT

TYPICAL USE

1203RL

#12 · 0.35mm

0.7mm

3

Yes, built-in

EO Gas · ISO 11135

Universal cartridge grip

Fast medium lines, flowing script, quick detail fills

1205RL

#12 · 0.35mm

0.7mm

5

Yes, built-in

EO Gas · ISO 11135

Universal cartridge grip

Bold everyday outlines, one-pass traditional lines

1207RL

#12 · 0.35mm

0.7mm

7

Yes, built-in

EO Gas · ISO 11135

Universal cartridge grip

Strong outlines with smooth flow, lettering

1209RL

#12 · 0.35mm

0.7mm

9

Yes, built-in

EO Gas · ISO 11135

Universal cartridge grip

Heavy outlines and filling small tattoo elements

1211RL

#12 · 0.35mm

0.7mm

11

Yes, built-in

EO Gas · ISO 11135

Universal cartridge grip

Very bold borders, fast solid small fills

1214RL

#12 · 0.35mm

0.7mm

14

Yes, built-in

EO Gas · ISO 11135

Universal cartridge grip

Maximum-width hollow lines, blackwork borders

Built Like a Medical Device, Priced for Wholesale

We control every step in our own factory, from needle grinding to sterile packing. Here is what goes into each turbo round liner cartridge.

01 Open-Center Channel, Machine-Soldered

The middle of the grouping is left open, forming a channel that holds and feeds ink while the outer needles line. We machine-solder every grouping so the channel sits dead center — an off-center channel feeds one side of the line more than the other.

02 Safety Membrane System

A medical-grade silicone membrane sits inside every cartridge. It keeps needle tension steady through fast, long lining sessions and stops ink and body fluids from flowing back into the grip and machine.

03 Polished 304 Needle Tips

We use Japanese-imported 304 surgical steel with mirror-polished tips. Smooth, sharp points mean clean penetration and less friction in the skin. Each grouping is soldered by machine, so the recessed center is identical across every batch.

04 Medical-Grade Housing

The shell is medical-grade polymer with a clear tip, so artists see the ink channel working while they line. Low-friction inner walls keep the needle stable. The standard fitting works with most rotary machines and cartridge grips.

05 EO Gas Sterilization

Every cartridge is sealed in its own blister pack and sterilized with EO gas. Our sterilization process is validated under ISO 11135, with batch records kept for full traceability.

06 Two-Stage Quality Control

Every unit passes 100% visual inspection on the line. Then 30% of each batch is checked again under 100x microscopy for tip alignment, solder quality, and center-channel depth.

Why the Open Center Lines Faster

In a tight liner, every needle meets at one point and ink rides on the outside of the grouping — it runs out fast. Open the center and the grouping becomes its own ink well: the channel feeds the outer needles through the whole stroke, so a bold line stays saturated from start to finish with fewer dips. Fewer dips means steadier speed, smoother edges, and fewer passes over the same skin. The line lands bold like a big liner, but with a slightly softer edge that many artists prefer for traditional and lettering work.

Where Hollow Liners Work Best

One job: bold lines at speed, with fewer dips. If the design is outline-driven and time matters, this is the needle.

Traditional & Old School

Bold outlines that stay saturated through long strokes — corners, curves, and circles all land as dense as straight lines.

Lettering & Script

Long letter strokes punish any drop in ink flow. The center channel keeps saturation even from the first stroke to the last — no dry tails

Filling Small Elements

Hollow liners do double duty: they outline and they fill. Small solid shapes — stars, dots, hearts — pack fast without switching needles.

Blackwork Borders

Big ornamental frames and borders mean very long lines. Less dipping keeps hand speed steady and sessions shorter.

Small Number, Fine Fast Line. Big Number, Bold Line Plus Fills.

Needle count sets the line width — and how much the turbo channel can fill. Match it to the job.

3RL – 5RL

Fast medium lines, flowing script

7RL

Bold everyday outlines, lettering

9RL – 11RL

Heavy outlines, small fills

14RL

Maximum-width hollow lines

Hollow RL vs Tight RL

The two opposite ends of the liner spectrum: one opens the center for flow, the other closes it for control.

HOLLOW RL

TIGHT RL

Grouping

Looser — center left open as an ink channel

Closely packed — all needles in one point

Ink Flow

High — flows through the open center

Restricted and focused — steady delivery

Feel

Looser internal layout, less resistance

Firm, compact, highly controlled

Line Result

Bold and smooth, slightly softer edge

Tight, crisp, maximum precision

Typical Gauge

Usually #12 (0.35mm)

#08, #10, or #12

Best For

Bold outlines, lettering, fast one-pass lines, small fills

Fine lines, micro detail, precise linework

Compare with the rest of the liner family: Round Liner (RL) cartridges, Tight Round Liner cartridges, and Turbo Round Liner cartridges — a close relative that recesses the center needle instead of opening the channel.

Our Certifications

R&G Bio is an integrated manufacturer with verified FDA registration, ISO 13485 / ISO 9001 certification and EU RoHS compliance — the documentation your market actually requires.

U.S. FDA RegisteredEstablishment No. 3009392898 CE — RoHS VerifiedEU 2011/65/EU Compliant ISO 13485:2016Medical Device QMS Sterile · EO GasSingle-use, batch traceable
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  • CE Rohs
  • FDA
  • ISO 9001
  • ISO 13485
  • Verified quality system — ISO 13485 / ISO 9001 certified factory, fully batch-traceable
  • Global market access — U.S. FDA registered, EU RoHS verified documentation
  • Custom certification support — if your market requires additional qualifications, we can assist in obtaining the relevant certifications. Contact us to discuss your requirements

Wholesale & OEM Programs

Factory-direct supply with full batch traceability. Tell us your sizes and target volume — we reply within 12 hours with a full quotation.

Wholesale MOQ bulk tattoo cartridge boxes

MOQ from 1,000 pcs

Standard sizes start low; mixed sizes allowed in one order.

Tiered factory pricing volume discount

Tiered Factory Pricing

The more you take, the lower the unit cost. Full price ladder with every quotation.

Fast lead time factory shipping

Fast Lead Time

Standard sizes ship from running production; OEM timelines confirmed with your quote.

Private label OEM packaging design

Private Label & OEM

Your brand, built on our production lines — in-house design and engineering support.

Explore the Wholesale Program OEM / Private Label

Qualified B2B buyers can request a free sample kit before committing to an order.

FAQs

Hollow RL removes the center needle from a standard round liner configuration. That leaves a hollow core running through the middle of the grouping — a circle with an open center instead of a solid cluster.

That open center acts as an extra ink reservoir. As the needle group enters the skin, ink flows from the outer ring of needles and from the hollow middle simultaneously. The result: a bolder, more saturated line per pass using the same needle count as standard RL.

Three things stand out. First, more ink flow. The hollow center stores extra ink, so you dip less often and lay down more pigment per stroke. Second, fewer passes to achieve the same saturation. Third, less skin trauma because you are not going over the same area as many times.

For artists who do bold outlines or large-scale work, those fewer passes add up across a session. Less fatigue for you, less trauma for the client, and typically cleaner healing.

The line reads slightly bolder than standard RL of the same count and diameter. The hollow center pushes more ink into the skin, so the deposited line spreads a touch more on contact. Most artists describe a 5RL Hollow as sitting between a 5RL standard and a 7RL standard in visual weight.

If you want bold outlines without bumping up your needle count, Hollow RL gives you that extra density while keeping the grouping compact.

Yes, and that is where a lot of artists find its real value. The hollow core releases ink in a softer, more diffused pattern than a solid liner grouping. That makes Hollow RL useful for shadow fills, soft black-and-grey transitions, and styles that blur the line between lining and shading.

It will not replace a dedicated shader, but for artists who like to handle both tasks with one cartridge, Hollow RL covers both bases.

Hollow RL runs on any rotary or pen machine that takes standard cartridges. The open center means slightly less surface resistance than a solid grouping of the same count, so the needle cycles with less drag.

Most artists run Hollow RL at their standard lining voltage. If anything, you can drop it slightly because the needle moves more freely and deposits ink more efficiently. Test on practice skin first to find your sweet spot.

Hollow RL comes in counts from 3RL to 14RL, across all three diameters: #08 (0.25 mm), #10 (0.30 mm), and #12 (0.35 mm). The 5RL, 7RL, and 9RL Hollow configurations are the most popular for general tattoo work.

For bold traditional outlines, 9RL or 11RL Hollow in #12 delivers heavy lines with minimal passes. For softer, more nuanced work, 5RL Hollow in #10 gives you a line that sits between fine and bold.

No. We built a proprietary stabilization system into every Hollow RL that maintains needle alignment throughout the stroke. The open center does not compromise structural integrity. Needles stay true, lines stay straight.

Our membrane system also prevents backflow, so the open center creates no additional contamination risk. Safety standards match every other cartridge in our lineup.

CE Mark, FDA Registered, KFDA Approved, ISO 13485, RoHS Compliant. We ship the paperwork you need for wherever you’re working.

Private labeling, custom needle setups, OEM/ODM. Drop us a line and tell us what you need.

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About R&G Bio

Built on Precision.
Trusted Globally.

01

Where Precision Meets Medical-Grade Standards

ISO 13485 certified facility with ISO Class 100,000 cleanrooms. 316L surgical steel, complete traceability.

02

End-to-End Manufacturing Control

From needle configuration to sterile packaging, every step is precision-controlled with automated assembly and batch tracking.

03

Meeting International Regulatory Standards

CE Mark, FDA Registered, KFDA Approved, ISO 13485, RoHS Compliant. Full documentation for global market entry.

04

Trusted Tattoo Needle Manufacturer Since 2009

15+ years serving 50+ countries with premium cartridge tattoo needles and flexible OEM/ODM solutions.

Premium Tattoo & PMU Supply
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OEM / ODM SERVICES

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