The clinical approach
Nanoseconds, not milliseconds
Tattoo ink isn't a stain you can bleach out. It's granular pigment parked in the dermis, much of it locked inside macrophages, in particles far too large for the body to clear on its own. Warming it does nothing. Fracturing it does.
Selective photothermolysis is the principle underneath all of it, set out by Anderson and Parrish in Science, 1983. Match the wavelength to the target, keep the pulse shorter than the time that target needs to shed its heat, and the target takes enough energy to break while the tissue around it stays comparatively cool. Q-switching is the hardware trick that drags a Nd:YAG pulse down into that window. Our engineering notes state it plainly: take the energy a free-running rod would spill over hundreds of microseconds, squeeze it into single-digit nanoseconds, and peak power climbs by orders of magnitude while the joules never move. The particle gets a shock, not a bake. FDA consumer guidance describes what happens afterwards — the fragments are metabolised, excreted, or carried off to lymph nodes and other tissue.
Nanosecond or picosecond, and settle that before model numbers
The first fork in this purchase isn't QE-01 against QN-03. It's which pulse regime you're buying. Picosecond platforms shorten the pulse by another order of magnitude or more below the nanosecond window. The target and the wavelength logic don't change, but the balance of the interaction does: with the same energy delivered in a shorter burst, less of it bleeds away as heat during the pulse itself and a larger share of the work arrives as a photoacoustic shock, which tends to leave finer pigment fragments for the immune system to carry off.
The clinical literature leans that way. A prospective randomised study of 49 patients in the Journal of the European Academy of Dermatology and Venereology (2018) compared two picosecond systems against a nanosecond system and favoured the picosecond arm on clearance, with little separation on adverse effects and explicit caution about multicoloured work. The purchasing side is the other half of the decision: picosecond sources cost substantially more to buy and to keep serviced, and that gap has to be earned back by caseload. Nanosecond Q-switched Nd:YAG remains the mainstay for black and blue ink, for pigmented lesion work, and for any room where capital cost is the binding constraint. Both platforms on this site are nanosecond. If your business case genuinely requires picosecond pulses, rule us out here rather than three quotes later.
Ink colour picks the wavelength
Our device manuals map it without much ceremony. 1064 nm takes black, blue and green-blue. 532 nm takes red. Run both together and you cover coffee and brown. That pairing isn't brochure symmetry, it's absorption. Longer wavelengths also scatter less and reach deeper — the 600 to 1200 nm band behaves as the skin's optical window, which is exactly why dense black ink sitting deep is a 1064 nm job, and why 1064 nm is the more forgiving line on melanin-rich skin.
Fluence is where people get burned
Energy density is energy divided by spot area, and the spot regulator moves that figure faster than the energy dial ever will — hold the energy still, double the spot diameter, and fluence drops by a factor of four. Which means any inherited parameter set tells you nothing unless the spot size came with it. The full fluence worked example on the QN-03 spec page runs the numbers if you want them. There's a depth trade underneath that too: at the same wavelength and fluence, a larger spot penetrates further, which is why our manuals push operators above 2 mm for dermal pigment and reserve sub-2 mm spots for junctional nevi and scars.
Treatment protocol
Course length, and why the gap matters
FDA consumer guidance puts typical laser removal at 6 to 10 treatments, and says outright that green, red and yellow are the stubborn colours while blue and black are the cooperative ones. A 2021 double-centre retrospective by Cannarozzo and colleagues in Life followed 52 patients on a 6 ns 1064/532 nm system — fluence up to 10 J/cm2 for black and blue ink, up to 5 J/cm2 for coloured — and reported a mean of 4.6 sessions with a minimum eight-week interval. Quote a client a range. Never a number.
That interval isn't padding on the schedule. Shattered pigment has to be taken up by phagocytes and drained through the lymphatic system, and that takes weeks. Treat sooner and you're stacking trauma on skin that hasn't finished healing. You don't finish the course faster. You just raise your complication rate.
What one session actually involves
Consult, photograph, and write the parameters down — every setting, every pass, signed off by the client. Clean the area and make sure it's dry, because wet skin bleeds energy away before it ever reaches the ink. Select the wavelength for the pigment in front of you. Then test: our manuals call for 3 to 5 low-energy shots first, watching how that patch answers, and only then committing to a working setting. Keep the tip perpendicular. Overlap spots by roughly a third. Stop when the pigment whitens and lightens; obvious oozing means you've already gone too far.
Aftercare is unglamorous and it's most of the outcome. Site kept dry and untouched for a couple of days, no picking at scabs, strict sun protection until everything settles. Frosting, swelling and the odd blister are expected. Hyperpigmentation, hypopigmentation and scarring are the genuine risks, and they scale with careless fluence and with darker phototypes, where surrounding melanin competes for the same photons — our notes on post-inflammatory hyperpigmentation go further into that. Patch test those patients. Every time. The same restraint applies when a dermal pigment case shares the treatment room and the same handpiece.
Recommended equipment
QE-01 or QN-03, and what actually separates them
Both fire 1064 nm and 532 nm at nanosecond widths. Here's the split. The QE-01 runs an electro-optic Q-switch, a polarizer plus a voltage-driven crystal shutter inside the resonator, so pulse width stays pinned at 6 ns while you move energy up and down, and every trigger is one predictable shot. Our engineering archive records single-pulse output up to 800 mJ (≤800 mJ) at 1064 nm, a continuously adjustable 1 to 7 mm spot delivered through a seven-joint articulated arm, 1 to 10 Hz, flat-top beam, around 45 kg before the arm goes on.
The QN-03 is passive: 6 to 8 ns, 400 mJ single pulse at 1064 nm, with double and triple pulse modes stacking toward roughly 800 and 1200 mJ. Spot steps through seven fixed sizes from 1 to 4 mm at 1 to 5 Hz, and there's no articulated arm at all — one fewer optical train to align, and one fewer thing to pay for when it drifts. Worth being clear about what multi-pulse buys you: more total energy per trigger, not more single-pulse peak power. That last figure is fixed by the design. A heavy daily ink caseload with continuous spot control argues for the electro-optic route, and the QE-01 electro-optic Q-switch spec sheet carries the full table. A mixed pigment clinic watching capital cost argues for the QN-03. And the LN-01 isn't in this conversation at all, since millisecond pulses heat a target rather than shatter it.
Acceptance checks, safety, and the boring consumables
Before you sign anything, ask for the laser product classification file against IEC 60825-1 and the type-test report against IEC 60601-2-22 — the particular standard for laser gear used in surgery, cosmetics, therapy and diagnostics. Then check the unit in front of you rather than the datasheet: key switch, remote interlock, emergency stop, foot pedal. Confirm the eyewear covers 200 to 1080 nm — 532 nm is visible green light and perfectly capable of taking a retina with it. If you can borrow an energy meter, read the output at the handpiece. Thirty seconds there tells you more than any spec sheet.
Then the mundane half. Purified water fill, a full water change every couple of months, the flashlamp as a wear part, a spare fuse living in the power socket, a room kept dry and temperate with no reflective surfaces near the beam path. Metal jewellery comes off the patient. Compare the full tables on each product page in our catalogue before you spec a treatment room. Our service team supplies manuals, spares and remote operator training; tell us your market and we'll tell you which documentation applies there.
Frequently asked questions
How many sessions should I quote a client?
A range, with the caveats attached. FDA guidance says 6 to 10 treatments is typical; the 2021 Life series averaged 4.6 on a nanosecond 1064/532 nm platform. Ink density, depth, age, body site and the client's own clearance rate all move that. Amateur work generally goes faster than a saturated professional piece. Say so at consultation, not after the fourth visit.
Which colours are going to fight back?
Green, red and yellow, according to FDA guidance, while blue and black are the easy end. Cosmetic pigments in brows and lip lines deserve their own caution, since some are known to darken rather than lighten on the first pass. A discreet test shot before you work on a visible facial line is basic practice, not paranoia.
Is this safe on darker skin types?
With care, and with 1064 nm as the default. Epidermal melanin absorbs it weakly, so more of the energy survives the trip down to the ink. That isn't immunity. Keep fluence conservative, patch test, be sparing with 532 nm on higher Fitzpatrick types unless you have a specific reason, and tell the patient about the risk of temporary lightening or darkening before you start rather than after.
Can every tattoo be cleared completely?
No, and promising otherwise sets your clinic up to fail. FDA guidance is direct about it: some tattoos lighten rather than vanish, and removal carries a real risk of scarring. Plenty of clients only need enough fading for a cover-up, which is a far more achievable brief. Agree on which outcome you're aiming at during the consultation.
Does a bigger single-pulse number always mean a better machine?
It doesn't. Peak power is energy divided by pulse duration, and fluence is energy divided by spot area, so an ≤800 mJ ceiling figure quoted without a pulse width and a spot size tells you almost nothing. Ask for all three together, plus the beam profile. A flat-top beam spreads energy evenly across the spot, which is what gives you consistent results pass to pass.
Do I need a picosecond machine instead?
That depends on your caseload, not on the marketing. Picosecond pulses hold the published edge on clearance — the 2018 JEADV randomised comparison is the usual citation — though the same authors were cautious about multicoloured tattoos, and the devices cost considerably more to acquire and to service. If your work is mostly black and blue ink, or you are covering pigmented lesions and ink on one capital budget, a nanosecond Q-switched Nd:YAG platform is still the rational buy. If picosecond really is the requirement, say so at the first call: QE-01 and QN-03 are both nanosecond and neither will meet it.
References
- US FDA - Tattoo Removal: Options and Results (consumer update)
- Cannarozzo G, et al. Q-Switched 1064/532 nm Laser with Nanosecond Pulse in Tattoo Treatment: A Double-Center Retrospective Study. Life (Basel). 2021;11(7):699.
- Lorgeou A, et al. Comparison of two picosecond lasers to a nanosecond laser for treating tattoos: a prospective randomized study on 49 patients. J Eur Acad Dermatol Venereol. 2018;32(2):265-270.
- Anderson RR, Parrish JA. Selective photothermolysis: precise microsurgery by selective absorption of pulsed radiation. Science. 1983;220(4596):524-527.
- IEC 60825-1:2014 - Safety of laser products - Part 1: Equipment classification and requirements
- IEC 60601-2-22 Ed. 4.0:2019 - Medical electrical equipment - Part 2-22: Particular requirements for surgical, cosmetic, therapeutic and diagnostic laser equipment