Round Liner (RL) tattoo needles are one of the most essential tools in a tattoo artist’s arsenal. Known for their precision and crisp lines, RL needles are the go-to choice for outlines, lettering, and fine details. Whether you’re a beginner or a seasoned professional, understanding how RL needles work and when to use them is crucial for mastering the art of tattooing. In this guide, we’ll explore everything you need to know about RL needles in 2025, from their design and uses to choosing the best products, like the Mast SMP MAX Tattoo Cartridges.

Table of Contents
Introduction to Tattoo Needles
Tattoo needles come in different shapes and sizes, each serving a unique function. The main categories include:
- RL (Round Liner): Best for outlines and detailed line work
- RS (Round Shader): Great for shading and color blending
- Magnums: Used for large shading and filling areas
- Flats: Perfect for geometric work and bold lines
Among these, RL needles stand out as the most commonly used configuration for defining tattoo structure.
What is a Round Liner (RL) Tattoo Needle?
A Round Liner (RL) consists of multiple needles tightly grouped in a circular pattern. The tight grouping creates sharp, clean lines, making it ideal for outlines and precision-based designs.
Key Features of RL Needles:
- Needle Formation: Tightly grouped in a round shape
- Line Precision: Delivers clean and sharp lines
- Ink Flow: Designed for consistent ink delivery
When to Use RL Needles
RL needles are versatile but are particularly suited for:
- Outlines: Defining the tattoo’s structure
- Lettering: Creating crisp and legible words
- Fine Details: Adding intricate elements like small symbols
- Dot Work: Perfect for stippling techniques
Advantages of RL Needles
- Clean Lines: Ideal for precision-based designs
- Versatility: Works with black outlines and colored borders
- Efficiency: Consistent ink flow minimizes retouches
- Control: Offers artists confidence for delicate work
RL vs RS: Key Differences
While RL and RS needles may look similar, they serve different purposes:
- RL (Round Liner): Tight grouping for outlines and detail work
- RS (Round Shader): Looser grouping for shading and color packing
In short, use RL for outlines and RS for shading.
Spotlight: Mast SMP MAX Tattoo Cartridges

The Mast SMP MAX Tattoo Cartridges are premium RL cartridges designed for precision and stability. Trusted by professionals worldwide, these cartridges are engineered to deliver consistent results for both outlining and permanent makeup applications.
Key Product Features:
- Optimized for SMP Design: Ensures consistent puncture depth
- Effortless Holder Management: Easy disassembly and reassembly
- Global Artist Collaboration: Developed with input from professionals
- Durability: Long-lasting needle filament
- Continuous Innovation: Improved regularly based on feedback
Available Sizes:
- 0401RL = 0.18MM 1RL
- 0403RL = 0.18MM 3RL
- 0601RL = 0.20MM 1RL
- 0603RL = 0.20MM 3RL
- 0801RL = 0.25MM 1RL
- 0803RL = 0.25MM 3RL
- 1001RL = 0.30MM 1RL
- 1003RL = 0.30MM 3RL
- 1201RL = 0.35MM 1RL
Tips for Choosing the Right RL Needle Size
Choosing the right size depends on your project:
- 1RL: Ideal for ultra-fine lines and detailed work
- 3RL: Great for standard outlines
- 5RL: Works well for thicker outlines and bolder lettering
- 7RL and above: Suitable for heavy outlines in traditional tattoos
Summary Table
Needle Type | Best For | Advantages | Limitations |
---|---|---|---|
Round Liner (RL) | Outlines, lettering, fine details | Sharp lines, precision, control | Not suitable for shading |
Round Shader (RS) | Shading, blending, soft effects | Smooth gradients, soft penetration | Not effective for crisp outlines |
FAQs
1. Can RL needles be used for shading?
They can, but they are not ideal. RS needles are better suited for shading work.
2. What size RL needle is best for beginners?
Most beginners start with 3RL for outlines, as it provides a balance of control and visibility.
3. Are Mast SMP MAX cartridges good for outlining?
Yes, they are optimized for stability and consistent ink delivery, making them perfect for outlines.
4. Can I use RL needles for permanent makeup?
Yes, especially finer RL sizes like 1RL and 3RL, which are excellent for hair strokes and eyeliner work.
5. How do I know if I need a thicker RL needle?
If you’re working on bold traditional tattoos or thick outlines, opt for 7RL or larger.