Two cartridges marked 7 can solve opposite problems. A seven-point round liner gathers its points into a compact working footprint. A seven-point curved magnum spreads the points across rows to cover a broader area. Even if the two cartridges have the same individual wire diameter, they present different edges to the design. The same principle applies at the smallest scale. A 0.20 mm single-point cartridge and a three-point liner with 0.25 mm wires answer different questions about how much room a mark has and how much visual weight it should carry.
Start by naming the mark. Identify whether it is a boundary, a filled shape, a soft transition, or an isolated accent. Next read the diameter, count, arrangement, and taper as separate dimensions. Confirm the interface and exact cartridge with the machine documentation. The result is a short list of models you can compare on the job they are actually being bought to do. This guide gives you that framework for both tattoo and PMU, plus concrete stocking examples for studios and academies.
Contents
- Read the geometry before reading the code
- Diameter from number 04 to number 12
- Short through extra-long taper
- Round liner and round shader layouts
- Flat, magnum, curved and U-shaped layouts
- What geometry changes at the working surface
- Housing, interface and purchasing checks
- Choose the box for a real studio brief
- Set up a useful studio comparison
- Frequently asked questions
Read the geometry before reading the code
Diameter is the width of one wire
The diameter in a specification such as 0.25 mm describes an individual wire at its nominal full-width section. The point narrows toward its tip. Neither the full wire diameter nor the narrowest point measures the complete contact footprint of a grouped cartridge. In a three-point round liner, the three wires occupy a small area together. Their spacing and the degree to which the points converge are additional dimensions. This matters when you are comparing two boxes whose printed diameter and count look the same.
Count tells you how many working points there are
Count is useful when it is paired with layout. A three-point liner and a three-point shader each have three points. The liner concentrates its points for a more defined mark. The shader presents a more open cluster for work where the transition matters. Likewise, a seven-point liner and a seven-point curved magnum share the count but place those points differently. Use count as one field in the comparison, then look at the point arrangement or the manufacturer's drawing.
Decode a complete example
For the ATTO Thunder Pro 0803RL variant in this guide, 08 denotes the 0.25 mm diameter family, 03 denotes three points, and RL denotes the round liner configuration. In the Pinky Pro 0601RL, 06 denotes the 0.20 mm family and 01 denotes one point. Some PMU catalogs write 1R or 1RL alongside the metric diameter instead. Others position a taper abbreviation after the configuration. Each format can be useful once you identify the meaning of every segment for that series.
| Field | What it measures or identifies | Typical catalog example | What to compare when replacing a box |
|---|---|---|---|
| Individual diameter | Nominal width of one wire before it tapers | 0.25 mm or #08 | Match the metric diameter where published |
| Count | Number of points in the working group | 03 or three points | Keep the count fixed when comparing layout |
| Arrangement | How the points are organized | RL, RS, flat, magnum, curved magnum | Check the end view and point spacing |
| Taper | Length and profile of the narrowing region | Long or a stated length in mm | Read the actual length and point description for the series |
| Interface | How the assembly attaches and engages | Universal-style bayonet or threaded grip | Match the exact pen, grip and cartridge family |
| Box quantity | Number of individual units supplied | 10 or 20 | Compare the package required for trials or ongoing work |
Diameter from number 04 to number 12
Read the metric number before comparing sizes
In the coding convention used by the ATTO examples below, #04, #06, #08, #10, and #12 correspond to 0.18, 0.20, 0.25, 0.30, and 0.35 mm respectively. Some PMU families also offer other dimensions and present them only in millimeters. The numbers describe sizes, not a ladder of difficulty or quality. A larger diameter can make sense for a main contour within one family while a smaller diameter makes sense for an accent. Keep layout and count fixed if the objective is to understand what the diameter changes.
| Code family | Nominal wire diameter in this convention | Controlled comparison | Example decision |
|---|---|---|---|
| #04 | 0.18 mm | Compare two single-point cartridges of the same series with matching taper | Decide whether the smallest accent has enough visual presence |
| #06 | 0.20 mm | Compare 1RL options on a curved short mark | Assess a restrained point in an open design |
| #08 | 0.25 mm | Compare grouped liners with the same count | Assess the footprint of a compact structural line |
| #10 | 0.30 mm | Compare the same diameter across liner and shader layouts | Choose definition or a more open transition |
| #12 | 0.35 mm | Hold count and layout steady in a comparison | Evaluate whether the fuller footprint fits a broad contour or fill |
Small differences matter when the mark has little room
Think about two adjacent lines on an ornamental motif. The critical dimension is often the remaining space between those lines at the final design size. A narrower wire in a comparable layout may help a delicate accent fit. The same design may benefit more from moving or removing the adjacent accent. The purchasing comparison makes sense when the open space is already visible on an actual-size proof. Use a separate full-view image to decide whether the accent contributes at the viewing distance the client expects.
Larger diameter and larger count solve different jobs
Compare a compact cluster of three larger wires with a spread group of seven smaller wires. The first can still have the narrower working footprint because it concentrates the points. The second can cover a wider area because the points sit across a different shape. For a mixed tattoo station, this is why a compact liner and a curved magnum remain useful together. For a PMU station, a single-point model and a compact round shader can serve distinct roles even when both are selected for a small area. Compare the shape that needs coverage and the edge that needs to remain distinct.
Short through extra-long taper
Where the taper begins changes the point profile
Taper is the narrowing section from full wire diameter toward the point. For the same nominal diameter, a longer taper narrows over a greater distance. A shorter taper reaches the fuller profile over a shorter distance. That relationship describes geometry. A product can also have a more rounded or sharper point form, and two products with the same stated taper length can still have different profiles. Compare the actual drawing or stated taper length where available, especially when migrating a studio standard to another family.
Compare short, medium, long, and extra-long within a series
Taper labels work best as relative categories inside a named product line. A medium in one line may be close to a long in another. If the manufacturer provides a measured taper length, pair it with diameter and point profile in the purchasing comparison. If the measured length is unavailable, use the relative label as a clue and request the exact geometry when the job depends on it. A single supplier worksheet can also carry a given diameter in both standard and rounded point versions. Their shared diameter is only one part of the match.
| Label within a named series | Shape to look for | Good comparison setup | Why someone would check it |
|---|---|---|---|
| Short | Full wire width is approached closer to the end | Hold diameter and layout constant across two taper choices | Compare how the point profile suits a defined mark |
| Medium | Intermediate length in that product line | Use as the reference against the same line's shorter and longer profiles | Establish a familiar baseline when evaluating another option |
| Long | Narrowing extends farther up the wire | Compare the same count and grouping on one representative edge | Evaluate the longer profile for a recurring fine mark |
| Extra-long | Longest category in that series, where offered | Confirm actual length, point form and package specification | Avoid comparing labels alone when the point geometry matters |
| Unspecified | Product lists diameter and layout but omits taper detail | Use a manufacturer specification or controlled comparison | Avoid assuming the point is the same as another model with the same diameter |
Change taper without changing the whole workstation
If you are trying to solve an edge problem, compare two taper choices with the same diameter and layout on a compatible machine. The useful question is whether one presents the specific mark in a more repeatable way. Comparing a long-taper one-point model against a short-taper grouped shader adds differences in count, layout, and footprint that can dominate the result. That comparison can tell you which cartridge you prefer for the whole brief, but it gives limited information about taper by itself. Choose the comparison that fits the decision you need to make.
Round liner and round shader layouts
Single point and small round liner
A single point suits an isolated accent when a grouped footprint would occupy too much room. A compact grouped RL suits a contour that needs more visual weight. In small lettering, compare the main baseline and a thin terminal separately. A grouping that gives the baseline useful structure may be excessive in the terminal. In a PMU design, compare the role of a sparse accent with the role of a defined border through training and design review. Put each model in the purchase plan only if it solves a distinct recurring need.
Round shader and the open circular group
An RS arranges points more openly than a tight RL of comparable count. That makes the useful comparison one of edge and spacing. For a small area, compare whether the shader has room to build a broader visual mark while leaving an adjacent edge clear. The footprint of a compact RS can fit a tonal pocket where a curved magnum is wider than the available shape. Moving to a larger count makes sense when the artist repeatedly needs room for broader coverage and the design has the space.
Match product choices to two real marks
For a fine PMU accent, compare the Pinky Pro 0601RL, 20 cartridges with the fuller working footprint of a grouped option appropriate to the same equipment. For compact tattoo contours, the Thunder Pro 0803RL, 20 cartridges gives you a three-point 0.25 mm option to evaluate. Assign one job to each choice. For example, plan the smaller point around an isolated accent and the grouped liner around a clearly defined shape. Keeping those jobs distinct makes it easier to decide which box earns a permanent place at the station.
Flat, magnum, curved and U-shaped layouts
Flats keep the working points in one row
A flat group places points side by side. The row has a long dimension along the points and a shorter dimension across them. This can be useful when a design calls for a clear directional edge. Compare the row with the boundary it needs to fit. A flat strip on a geometric exercise gives a clearer demonstration of this relationship than an open swatch with no edges. If the working row is wider than the planned shape, choose a smaller grouping or revise the design. A flat group can also come with different point height profiles, so compare the end and side views.
M1 and M2 describe different row construction
Catalogs often use M1 for a staggered or weaved magnum layout and M2 for a stacked, closer two-row layout. Read the manufacturer diagram before treating the suffix as an interchange standard. Spacing and row position determine the shape presented at the working edge. For a broad panel, one design may make a gradual transition easier to observe. For a compact fill, a more concentrated footprint may fit the available area better. Compare two models of similar count if you want the layout difference to stand out. The nominal working width still depends on point spacing and individual wire size.
A curved magnum changes the edge profile
The RM or curved magnum usually presents a curved working edge across the group. The profile gives a tattoo artist a different edge to evaluate when the area transitions into open space. It also requires enough room for the overall width of the group. The Thunder Pro 1007RM, 20 cartridges is a seven-point option to compare with a compact shader for a tonal shape. A box makes sense for a studio that regularly sees enough space for that edge. For a small shaded island that meets several boundaries, compare the shape against a narrower group first.
A U-shaped row is its own configuration
U-shaped PMU groups can organize points along a curved single-row profile. The drawing and exact product designation matter because a U-shaped row and a curved two-row magnum can both look curved in a side illustration. A curved profile alone does not establish point spacing, tip width, or compatibility. Before ordering a U-family cartridge for academy demonstrations, identify how the instructor uses its working edge in the curriculum and verify the model for each machine. Choose it for the designed mark or transition where the layout earns its place.
| Layout family | Working geometry to verify | Representative job | What can change between models | Common replacement mistake |
|---|---|---|---|---|
| Flat | One row, often a straight edge | Defined directional shape | Point height and row width | Assuming the same count gives the same row length |
| M1-style magnum | Two staggered or weaved rows in a common naming system | Broad passage or fill test | Row offset, width, spacing, taper | Treating the suffix as a specification shared by every supplier |
| M2-style magnum | A closer stacked two-row layout in a common naming system | Compact broad coverage comparison | Density and actual working edge | Comparing only the number of points |
| RM or curved magnum | Curved working profile, often across two rows | Transition with space to feather its visual edge | Arc, spacing, and overall footprint | Buying the same count as a round group and expecting similar width |
| U-shaped or U-flat | Curved single-row family where documented | PMU exercise calling for that profile | Row geometry and interface | Substituting a curved magnum by visual name alone |
What geometry changes at the working surface
Think in footprints and edges
A group with a concentrated footprint focuses the marks into a smaller area. A spread group distributes them across a wider region. The artist sees the result through the mark, the neighboring spaces, and how the working edge meets a boundary. A point that suits one side of a design may cover too much of an adjoining narrow area. Use the original drawing to identify the widest and narrowest meaningful passages. If one tool can address both with control under the studio's working method, that group can do double duty. If each passage has different edge requirements, buy a second group for the clearly defined job.
Tissue response depends on more than the wire
Needle diameter, count, taper, and layout contribute to the way a grouping meets a surface. Tissue response also involves movement, the condition and location of the skin, the working technique, and the cumulative contacts in the area. A smaller wire specification alone does not quantify skin trauma, and a larger group alone does not establish that a procedure will be more traumatic. Use the manufacturer's intended use, supervised training, and direct assessment for work on people. Keep geometry claims focused on observable mechanical differences. For example, comparing the edge widths on a bench exercise can support a tool decision without making a claim about healing.
Compare edges at a design boundary
A broad gray passage on an open rectangle can make several models look suitable. A test shaped like the actual design tells you more. Draw a large area, a tapering wedge, and an adjacent line that must remain clear. Compare the two candidate groupings on identical synthetic material under the same lighting. Look for where the footprint begins to crowd the wedge and how the line remains visible at the boundary. If the wider group works well in the open area but loses precision at the wedge, keep the wide group for the broad part and assign the narrow group to the edge. The test gives you a reason to buy both.
Separate measured construction from technique claims
A specification can identify the steel used in the points or the sterilization process listed for an exact cartridge. Those are different facts from the visible mark or a claim about tissue outcomes. Where the ATTO product specifies 304 stainless steel and EO sterilization, use that information in the purchasing check for the named model. Review sealed packaging, labeling, and use instructions for the exact item. A clear housing helps with visual inspection of the assembly where specified. It has a different role from the shape of the needle grouping. Keep the benefits attached to the feature that provides them.
Housing, interface and purchasing checks
Verify the handpiece and grip before comparing points
A cartridge has to attach and engage correctly for its geometry to matter. Universal-style bayonet cartridges and threaded cartridges have different attachment designs. A pen family may also offer more than one grip. Name the exact grip you use, then confirm the cartridge family against the machine documentation. This matters when two studios use the same pen name but have different accessories. Confirm any shared cartridge choice with the complete machine and grip combination before buying boxes for every station.
Review the construction fields in the right order
Look at the package and exact variant for the count, diameter, arrangement, taper when published, interface, pack size, and sterilization labeling. Compare the membrane and housing details where those specifications affect what the studio needs. The membrane supports the cartridge's internal function and is separate from the barrier and handling practices required at a professional station. Choose the model that fits the machine and mark. Then evaluate the way a box is supplied, stored, and used under the studio's procedures.
Select the box size by how often the mark recurs
A small trial quantity is useful when a group solves a new problem and you have a clear comparison. For recurring contour work, the 20-cartridge variant may fit the purchasing rhythm better. A new academy cohort can make the decision especially concrete. Count the exercises that use the same grouping, the number of stations, and the documented allowance for demonstrations. A second grouping should earn its place by teaching a visibly different result. The combined list can stay short while giving students meaningful practice.
| Purchase checkpoint | Verify against | What a match lets you decide | Example mismatch |
|---|---|---|---|
| Exact machine and grip | Machine and cartridge documentation | Which physical interface you can order | A compatible family for a different grip on the same pen |
| Mark and geometry | Actual-size design or curriculum exercise | Which grouping serves the main job | Seven points shared by a liner and a curved magnum |
| Diameter and taper | Exact variant and geometry details | Which alternative can be compared on the same mark | Matching diameter and count with a different point profile |
| Sterilization and packaging | Individual package and manufacturer instructions | Whether the model fits the studio's handling requirements | Spec copied from a related family onto a different SKU |
| Box count | Exact option and expected recurring use | Trial box or standard reorder box | Matching model name with different package quantity |
| Studio acceptance | Comparison on the intended exercise and qualified review | Which group becomes the regular station choice | Broad swatch result that fails at a narrow design boundary |
Choose the box for a real studio brief
Fine-line tattoo appointments with a defined contour
Imagine a studio that books small lettering and botanical designs. The recurring problem is keeping the main curve readable while leaving room for a fine accent. Begin with the compact Thunder Pro grouped liner for the structural contour and test the fine accent as a separate tool choice. Draw a typical letter or leaf attachment. Compare the close-up and the normal-distance view. If the accent is already readable with the grouped liner, that grouping can carry more of the work. If the grouped footprint consistently crowds the accent, evaluate a compatible single-point option intended for that use.
Mixed tattoo work with broad tone and small boundaries
A second studio books small illustrative work that includes both a defined boundary and an interior shadow. The outline is compact, but the shadow opens up toward one end. Use a compact liner to compare how the boundary reads. For the shadow, put a small round group beside the 1007RM and see which fits the widest planned region and where it needs to give way to the smaller group. The wider group can make sense for the open passage. The compact option earns its place if there are several narrow tonal islands. Browse the ATTO tattoo cartridge needle collection when adding the second footprint.
PMU academy station with two visible teaching goals
An instructor wants students to distinguish an isolated fine accent from a shaded transition. Standardize the first exercise around one compatible point choice such as the Pinky Pro 0601RL where appropriate. Then choose a contrasting layout from the ATTO permanent makeup needle collection based on the exact mark and confirmed machine interface. Put the two intended outcomes next to one another in the worksheet. For the fine accent, look at visibility and separation. For the transition, assess coverage and edge quality on the training model. The comparison helps students understand a geometric reason to change tools.
Set up a useful studio comparison
Use one variable for the engineering question
Decide whether you are comparing diameter, point count, layout, taper, or the whole cartridge as an alternative for a brief. For a diameter question, keep the other geometry as similar as possible and use the same compatible machine. For a layout question, keep count and diameter comparable. For a full replacement question, compare the two complete products on a repeated mark and examine whether either changes setup or fit. A comparison can answer one question very well and leave another open. Align it with the decision you actually need to make.
Test the brief in its full shape
Print the design at actual size. Pick the meaningful contour, a compact fill shape, and an edge that transitions into open space. Put the line and the fill near a gap you want to preserve. After the comparison, look at the complete picture as well as the close-up. If a smaller group gives a beautiful isolated line but leaves the contour invisible from the intended reading distance, assign it to the accent. If a large group covers the open area well but crowds the border, assign it to that broad region. Keep the geometry aligned with the purpose of the mark.
Bring the result into purchasing and training
For stock that supports common work, prioritize models that reliably solve different jobs over a large set of near-duplicates. At an academy, keep the outcome of each grouping visible in the training exercise so students learn a choice they can transfer to new designs. At a mixed studio, separate common geometry from exact machine fit. Several stations can share a lesson about layout even when they use different compatible assemblies. Start a new comparison when a repeated brief adds a shape that existing groupings struggle to fit.
Frequently asked questions
Is a #08 always 0.25 mm?
It is 0.25 mm in the specific code convention and ATTO examples discussed here. Confirm the metric diameter on the exact variant when comparing suppliers. A diameter match gives you a useful starting point. Then compare point count, layout, taper, and fit to see whether the full assembly matches the job.
Does 0803RL make a line 0.25 mm wide?
The 0.25 mm figure describes each individual wire in the cited three-point ATTO grouping. The line comes from the group as a whole and the way the mark is formed. Compare the assembled footprint and use a reference line of the actual project size when judging whether it suits the design.
Can I use a three-point shader in place of a three-point liner?
They can both make marks in a small area, but their layouts serve different edge goals. A tight liner is the more direct choice when a boundary needs definition. An open shader is useful when there is room for a less concentrated footprint. Compare the model with the specific boundary or tonal shape you want to create.
When is an extra-long taper worth comparing?
It is worth comparing when the point profile matters to a repeated fine mark and you have a comparable geometry in another taper. Read the actual length where provided. A medium or long in a different catalog can be more similar than the names suggest. Start the comparison with the same diameter and arrangement.
How do I tell a curved magnum from a U-shaped cartridge?
Review the manufacturer's grouping drawing for the exact model. A curved magnum typically uses multiple rows with a curved working profile. A U-shaped PMU family can use a curved single-row arrangement. The point arrangement, working width, and attachment are the dimensions that determine whether a cartridge fits your job.
What do M1 and M2 tell me?
They commonly distinguish a staggered or weaved magnum from a tighter stacked magnum arrangement. Use the suffix as a prompt to examine the exact row configuration. Look at spacing and the full working edge before buying either for a specific shape.
Will the same cartridge fit every machine described as universal?
Confirm the exact cartridge and exact machine grip using the manufacturer's compatibility guidance. Similar-looking housings or a common grouping label do not establish fit. A 1RL label describes the working points. It does not describe how the assembly attaches or engages with the handpiece.
Should I buy a trial quantity or twenty cartridges?
Start with the quantity that lets you answer a defined question if the job or group is new. When the grouping already solves a recurring contour or transition and the exact variant is confirmed, a 20-cartridge box supports repeat use. Compare cost per individual unit and the units required for the recurring workload.
What should I put in the first mixed tattoo and PMU order?
List the main marks for each station and verify the machine and grip separately. A grouped tattoo liner, a wider tonal choice for tattoo shapes that need it, and a compatible fine-point choice for PMU exercises can give the studio distinct working footprints. Add a second PMU layout when the course or appointment list has a defined transition that requires it.