If you have questions about stroke length in permanent makeup machines, we have the answers - read on to find out what stroke length is, why it’s so important, and how to find the machine with the right stroke length for you!

The stroke length of a rotary machine refers to the length the needle moves on its path in and out of the cartridge housing. For example, a 3mm stroke length means that when positioned neutrally, the needle will extend from the tip of the cartridge by 1.5mm and be drawn 1.5mm back into the cartridge.



Stroke length affects how fast the needle moves, how hard it hits, and how long you can have your needle depth (also known as hang). It also affects how much pigment clings to the needles - shorter stroke lengths which spend less time inside the cartridge will pick up less pigment from the cartridge reservoir.

When needles have more distance to travel, they move more slowly and have greater momentum and power, resulting in a harder “hit”. They’ll also penetrate the skin more easily, allowing skilled PMU artists to work quickly, but in unskilled hands this can cause trauma. Shorter stroke lengths move faster but hit more softly, which makes them perfect for the delicate skin found on the face, especially around the eyes.

It’s important to make sure your stroke length and needle depth match up - luckily, most PMU machines contain an adjustable needle depth, so you can make sure that the needle is inside the cartridge for long enough to pick up pigment. A needle hang that’s too short can also cause problems if the stroke length is particularly long, as pigment will puddle on the skin and make it harder to see your work.



Most permanent makeup machines come with a fixed stroke length, and are suitable for specific purposes. Machines with a short stroke length between 1.8 and 2.5mm create a soft effect, with multiple passes needed to build up smooth layers of pigment - this stroke length is ideal for softly shaded brow and lip treatments, but may not be effective on particularly thick, oily or tough skin. Lip tissue especially is prone to swelling and lymph production as a result of trauma, meaning a shorter stroke length is optimum.

A stroke length is considered medium if it’s between 3 and 3.5mm - the resulting hit is not too hard and not too soft. These are typically used for brow treatments and by experienced, confident technicians.

Longer strokes start at around 4mm; they’re highly effective for packing pigment but can easily cause trauma to the treatment site if you apply too much pressure. A longer stroke length allows you to hang the needle out of the cartridge further, giving you greater accuracy and control, but should only be used by experienced artists!



Artists would typically only use a stroke length of 4mm and above for treatments such as scalp micropigmentation, areola restoration or scar camouflage on the body. However, a high stroke length like this would only be suitable for experienced PMU artists with a high skill level, who feel confident using a harder-hitting machine.

For PMU artists who offer a variety of techniques and treatments, you may find the best solution is to invest in machines with different stroke lengths for different purposes. For example, if your signature is soft, powder brows, you’ll want a machine like the Microbeau Bellar Air with a short stroke length of 2.1mm. If you then wanted to add multiple brow styles and techniques to your treatment menu, you would pick up a machine with a longer stroke length, like the 3.5mm Bishop PMU Pen.

Some PMU machines come with an adjustable stroke length, such as the Peak Astra, which can be used with 2.5, 3.5 or 4mm stroke length cams - this means you can adjust the machine between treatments instead of having to switch out to another. This is ideal for experienced artists who offer multiple treatments and techniques.



Understanding your tools in the PMU industry is key to carrying out safe treatments and producing the best possible results. If you’re looking for more information or free educational content, make sure to check out our blog and subscribe to our YouTube channel. Or if you can’t find what you’re looking for, drop us an email at [email protected].

And that’s just about everything you need to know about how stroke length works and how to make the right choice for your permanent makeup business!