Setting up the Apollo: one impression at a time.

An SMP machine setting is the combination of voltage, stroke and hand speed that produces one impression of one size at one depth, then produces it again thirty thousand times. A tattoo machine is set up to draw a line, and an SMP machine is set up to place a point and leave. Every number on the power supply and every habit in the hand is judged by whether the last mark of the session matches the first.

The Apollo, which I co-designed with Microbeau International as the first machine engineered solely for SMP, fixes two of those three variables in the hardware. The stroke is 2.3 mm, chosen for the shallow single impression, and the weight is 106 grams so the hand is still steady in hour seven. The artist still has to set the voltage, control the hand and test the setup before touching a client.

Voltage is a range

The machine runs across a 4 to 9.5 volt range and places the same impression at the bottom of it as at the top. Voltage sets how hard and how often the needle cycles; it does not set the size of the mark. Lower voltage is slower and softer, and most scalp work lives there, because a slow cycle gives the hand time to place each impression and lift before the next. Higher voltage is for skin that resists entry, and it demands a faster hand to keep the impressions from stacking.

There isn’t one voltage to memorise. The right setting depends on the skin in front of you and the cartridge in the machine. Start low and raise it in small steps, and only when the needle is not entering cleanly at the depth you want. An artist who learns one voltage and runs it on every head is running the wrong voltage on most of them.

Stroke and depth

The stroke is fixed, so what the artist controls is how much of it reaches the skin, through the angle of the machine and the pressure of the hand. The target is the papillary dermis, the thin band under the epidermal junction where pigment stays put. Go shallower and the impression exfoliates out within months; go deeper and it migrates and blurs into the marks beside it.

The right depth feels like a needle that enters with almost no resistance and comes out clean, leaving a small, crisp point of pigment and hardly any bleeding. Resistance on entry means the angle is too steep or the hand too hard, and a halo around the healed mark means it went too deep. Learn the feel on practice skin, because on a person the feedback arrives weeks later, healed.

Hand speed, which no dial controls

With voltage and stroke settled, the hand decides the rest. Too fast and impressions stack into short lines, the tattoo stroke SMP exists to avoid. Too slow, with too much dwell, and each impression takes more pigment than it should and heals heavy. The rhythm to learn is place, lift, move, so the needle is in the skin for one cycle, out, and repositioned before the next.

The healed field shows which happened. A hand that moved evenly leaves marks of one size at one spacing, a hand that hurried leaves a texture the eye picks out as pattern, and a hand that dragged leaves dashes.

Warm-up and testing

Before every session, run the machine off the skin and listen. The cycle should be even, with no stutter as the voltage changes. Fit the cartridge and check the needle protrudes as far as you expect. Then place a row of impressions on practice skin at the voltage you intend to use, a row at half a volt either side, and compare them. If the three rows differ in size, the machine or the cartridge is inconsistent and the session waits.

The hand needs warming too. The first hundred impressions of a session are rarely as even as the next thousand, so they go on practice skin rather than on the hairline. In our studio that strip of practice marks sits on the bench beside the client’s chair at every session.

Holding the machine

Hold it as you would a pen you intend to write with for seven hours, close to the tip for control, without a grip that tightens the forearm. Let the angle between machine and skin follow the curve of the head, so the needle meets the skin the same way at the temple as at the crown, and keep it consistent within an area, because a changing angle is a changing depth. If your shoulder is up by your ear at the end of the first hour, the grip is wrong and the marks will show it by the third.

Hairline, density, scars

At the hairline and in scars, we ease the settings back. The hairline takes the lowest voltage the needle will enter at, the slowest hand and the lightest touch, because every impression there is judged on its own against bare skin. Density work can carry a slightly firmer hand and a steadier rhythm, because behind the hairline the eye takes in the field as texture. Scar tissue takes the lightest of everything. It is denser, less elastic and holds pigment unpredictably, so it is built in more passes with less in each and revisited at the final refinement.

The beginner errors

The three common errors tend to happen together. Moving too fast stacks impressions into lines. Working too deep lets them blur and migrate, leaving a halo around every healed mark. Too much pressure pushes the needle past the depth the stroke was chosen for, so you lose the machine’s consistency. All three come from tension, and tension comes from working on a person before the sequence is automatic on practice skin.

The case for a machine built for the act is in SMP machines: built for it, or borrowed. The machine places the mark, the colour theory decides what is in it, and the method decides where it goes across a minimum of three sessions, including the final refinement, ten to fourteen days apart.

In the three-day intensive, I work over students’ shoulders as they set up the machine, on practice skin before a live model, and the first thing most of them change is the number they walked in with. Start with SMP training, or with the online course if you would rather have the theory before the chair.

What voltage should an SMP machine run at?

There is no single voltage to memorise. The Apollo runs across a 4 to 9.5 volt range and places the same impression at either end. Most scalp work lives at the lower, slower end, because a slow cycle gives the hand time to place and lift. Start low and raise it in small steps only when the needle is not entering cleanly.

How deep should SMP pigment go?

The target is the papillary dermis, the thin band under the epidermal junction where pigment stays put. Shallower and the impression exfoliates out within months; deeper and it migrates and blurs into the marks beside it. The right depth feels like a needle that enters with almost no resistance and leaves a small, crisp point with hardly any bleeding.

Why does SMP heal in lines instead of dots?

Because the hand moved too fast and the impressions stacked into short lines, the tattoo stroke SMP exists to avoid. No dial controls hand speed. The rhythm to learn is place, lift, move, so the needle is in the skin for one cycle, out, and repositioned before the next. A hand that dragged leaves dashes instead.

How do you test an SMP machine before a session?

Run it off the skin and listen for an even cycle with no stutter as the voltage changes, then check the cartridge protrudes as expected. Place a row of impressions on practice skin at your intended voltage and a row at half a volt either side. If the three rows differ in size, the setup is inconsistent and the session waits.

What are the most common beginner SMP mistakes?

Three errors that tend to arrive together: moving too fast, which stacks impressions into lines; working too deep, which lets them blur and leaves a halo around every healed mark; and pressing too hard, which pushes the needle past the depth the stroke was chosen for. All three come from tension, and tension comes from working on a person before the sequence is automatic on practice skin.

Sources

• NCBI Bookshelf, Histology, Dermis
• Microbeau International, Apollo SMP