Tattoo Needle Sizes Explained: Diameter, Count and Cartridge Codes

Tattoo needle size is a combination of individual needle diameter, needle count and grouping—not one number. In the common code 1205RL, 12 denotes a 0.35 mm individual needle diameter, 05 means five needle points, and RL means Round Liner. Check the manufacturer’s naming system before applying that interpretation to another product. Taper and machine compatibility require separate checks.

For tattoo artists and apprentices comparing cartridges, the practical sequence is: identify the task, read the full configuration, compare like-for-like options, then confirm the exact product and equipment fit. A cartridge code alone cannot tell you the finished line width.

Tattooing in progress. Photo by Oleksii Piekhov / Unsplash. The cartridge specification is not identified in this photograph.

What does each part of a tattoo needle code mean?

A code such as 1205RL describes three separate specifications. Reading “12” as the needle count would lead you to order the wrong configuration.

The Yes Needle Round Liner listing writes this configuration as 12/05 RL. The slash and spacing separate the fields; they do not add another size specification.

Code-reading illustration, not a drawing of the actual needle arrangement or a measured line sample.

Tattoo needle diameter chart

Diameter means the thickness of one individual needle. It is different from the width of the complete group. FK Irons’ technical glossary provides the following number-to-diameter mapping.

Use millimetres when comparing suppliers. Descriptions such as “bugpin,” “standard” or “fine” should prompt you to check the numeric specification, rather than substitute for it.

Do not confuse #12 diameter with 12 needles, or 0.35 mm diameter with 0.35 mm finished line width. Record each field separately in your supply notes.

What is the difference between 3RL, 5RL and 7RL?

3RL, 5RL and 7RL identify different needle counts within the Round Liner grouping. Those shortened names do not tell you the diameter or taper. Before comparing them, recover the complete product codes.

Two useful comparisons answer different questions:

These are label comparisons, not controlled performance tests. Construction, taper and other product details can still differ. Avoid comparing products that change several specifications at once and then attributing the result to count alone.

For a replacement order, “the same 3RL” is incomplete. Keep the brand, series, full code and confirmed taper with your order record.

What do RL, RS, M1 and CM mean?

Grouping describes the arrangement of the points. It helps identify the product family to investigate, but does not establish machine compatibility.

FK Irons’ glossary distinguishes tight round liners, looser round shaders and curved magnum profiles. Abbreviations vary between catalogues; RM, MC and CM should be checked against each manufacturer’s definition rather than assumed identical.

For brand-specific examples, Yes Needle lists M1 cartridges for fills and larger-area shading, and CM cartridges for shading and transitions. Those are supplier-described applications, not comparative test results. The RS explanation above is terminology, not a claim that Yes Needle sells an RS cartridge.

Does the code tell you the taper?

Not necessarily. Taper is the narrowing section leading to the point, and it needs its own specification. A label containing diameter, count and grouping may leave taper unstated. FK Irons explains taper separately from diameter and grouping.

If a supplier uses “long taper,” ask for that product’s definition or stated length when it matters to your comparison. Do not fill an empty specification with another brand’s measurement. In particular, a missing taper suffix is not sufficient evidence to assign a specific taper to a Yes Needle cartridge.

How should an artist choose a cartridge size?

Start with the part of the design you need to execute, then compare configurations within that task. “Fine line,” “portrait” and “traditional” are broad style descriptions; each design can contain several different requirements.

Use this worksheet to create a shortlist, rather than treating it as a universal size prescription.

For example, if you are comparing two liners for the same detail, first check whether you are changing diameter, count or both. If you are choosing between a liner and a magnum for different parts of a design, document those tasks separately rather than looking for one “best size.”

For supervised practice, keep a short observation record: exact cartridge, machine and grip, practice material, task and observed result. When you change supplies, note what changed. This makes later comparisons more useful than remembering only that one cartridge “felt finer.” Practice-material observations should remain labelled as such; they do not establish healed results on skin.

Can you convert a needle code into an exact line width?

A needle code is not enough to calculate the finished line width. It identifies product specifications, while a line-width claim describes a result that needs its own evidence.

Before relying on a line-width chart, check whether it includes actual samples, the complete cartridge specification, the material used, the measurement method and whether the result is fresh or healed. A computer-drawn line labelled “5RL” does not demonstrate what that cartridge produced.

Use a code chart to identify the product. Use clearly documented samples and appropriate professional guidance to evaluate results. Keep those two decisions separate.

What should you confirm before ordering?

1. Full configuration: individual diameter, count, grouping and confirmed taper.
2. Equipment fit: the particular cartridge, machine and grip, using their relevant instructions.
3. Box contents: one configuration or an assortment, and the quantity covered by the listing.
4. Product version: the current item, rather than a remembered code or old photograph.
5. Unresolved specifications: obtain clarification before treating two products as replacements.

For the configuration comparisons in this guide, the Yes Needle RL page lists 06/03, 08/03, 10/03 and 12/03 RL, plus several #12 counts. Compare the exact option you need; verify availability and remaining specifications before ordering.

Frequently asked questions

Does 1205RL mean twelve needles?

No. In the naming convention explained here, 12 is the diameter code, 05 is the five-point count and RL is Round Liner. Check the supplier’s code system before decoding unfamiliar labels.

Are all 3RL cartridges interchangeable?

No. Three points do not establish identical diameter, taper, construction or equipment fit. Match the complete specification when replacing a cartridge.

Is the smallest needle count always best for fine-line work?

Count alone is insufficient. Define the detail and line hierarchy, then compare diameter, grouping, taper and the particular product. “Smallest” is not a complete selection rule.

Does CM mean a cartridge fits every tattoo machine?

No. CM is a grouping label in the product range discussed here. Check machine and grip compatibility separately.