Tattoo ink is not one substance. A single tattoo can contain half a dozen different pigments, and each of them absorbs light differently. That is the whole reason a clinic treating a multi-coloured piece with one laser will clear some of it and leave the rest sitting there, sometimes after a full course of sessions.
This explains what wavelength actually does, why picosecond and Q-switched lasers behave differently, and how the choice of device is matched to the ink in front of it.
Why does ink colour change which laser is needed?
Because a pigment only breaks down when it absorbs the light aimed at it, and each pigment absorbs a different part of the spectrum. A wavelength that is strongly absorbed by black ink can pass almost straight through green ink without doing much at all.
Laser tattoo removal works by delivering energy fast enough to shatter ink particles into fragments small enough for the body to carry away over the following weeks. The energy has to be absorbed by the pigment for that to happen. Point the wrong wavelength at a colour and the ink simply does not take up enough energy to break.
Which colours are straightforward and which are not?
Black and very dark inks are the most cooperative, because they absorb light broadly across the spectrum rather than in a narrow band. This is why a plain black tattoo is usually the simplest case and why almost every clinic can make progress on one.
Colours are where the differences show. Reds, oranges and yellows respond to shorter wavelengths, while greens and blues sit at the other end and need a wavelength that most single-device clinics do not have. Green in particular has a reputation for stubbornness, and it is usually a wavelength problem rather than a lack of effort.
White, flesh tones and some pastel inks bring a different issue. Certain pigments contain compounds that can darken rather than lighten on first exposure, so they are approached carefully and tested first.
What is the difference between PicoSure, PicoWay and Q-switched lasers?
Mainly the length of the pulse, and that changes how the ink breaks. Q-switched lasers deliver energy in nanoseconds, billionths of a second. Picosecond lasers such as PicoSure and PicoWay deliver it in picoseconds, a thousand times shorter again.
A longer pulse works largely through heat. A much shorter pulse delivers its energy before the heat has time to spread, so more of the effect is mechanical, shattering the pigment rather than cooking it. In practice that tends to mean smaller ink fragments, which the body finds easier to clear, and less heat spreading into the skin around the ink.
The two picosecond systems are not interchangeable either. They offer different wavelengths and different handpieces, which is what makes it possible to match the device to the specific colours in a tattoo rather than treating everything the same way.
Does a shorter pulse mean fewer sessions?
Not automatically, and anyone promising a number before seeing the tattoo is guessing. Pulse duration is one variable among several. Ink density, how deep it was placed, how old it is, where it sits on the body and how well your lymphatic system clears the fragments all affect the outcome. What the right wavelength does reliably is make progress possible on colours that would otherwise barely move.
Why does a single-laser clinic struggle with a coloured tattoo?
Because one device covers a limited range of wavelengths, and a multi-coloured tattoo needs more than one. A clinic with a single laser has to treat every colour with the wavelength it owns. Black will fade, and the colours it cannot properly reach will stay, often described afterwards as a tattoo that “stopped responding”.
Working with more than one system means the pigment decides the device rather than the other way round, and different colours within the same tattoo can be treated with the wavelength that suits them.
Does skin tone change which laser is used?
Yes, and it is one of the more important parts of the assessment. Melanin in the skin absorbs laser light too, which means a wavelength strongly absorbed by melanin carries more risk of affecting the surrounding skin in richer tones. Longer wavelengths are absorbed less by melanin, which is why they are generally preferred for darker skin types.
This is why a patch test is carried out before treatment rather than treating on the day. It establishes how your skin responds at a given setting before anything is done to the tattoo itself.
How is the right laser chosen for your tattoo?
At the consultation, by looking at what is actually in the skin. The assessment covers which pigments are present, how densely the ink was packed, whether it was applied by a professional or an amateur, how old it is, whether there is scarring from the original work, where on the body it sits and what your skin type is.
That produces a plan that may use different devices on different parts of the same tattoo, and it may change as the piece responds. Reviewing the response between sessions and adjusting the approach is part of the process rather than a sign something has gone wrong.
What affects how long a course takes?
Sessions are spaced to give the body time to clear the shattered pigment, so the interval is not something to rush. Beyond that, the variables that matter most are:
- The colours present, since some clear faster than others
- Ink density and layering, including any cover-up work over an older tattoo
- The age of the tattoo, as older ink has usually faded somewhat already
- Its position on the body, since areas with better circulation tend to clear faster
- Whether the aim is complete removal or fading for a cover-up, which needs far less work
An honest estimate comes after seeing the tattoo, not before.
What does treatment and recovery involve?
Most people describe the sensation as sharp and quick, often compared to an elastic band snapped against the skin, and treatment of a small tattoo takes minutes rather than hours. Immediately afterwards the area usually looks white for a short period as the ink fragments, then becomes red and swollen like a graze.
Aftercare is straightforward. Keep the area clean and covered as advised, leave any blistering alone, and protect it from sun between sessions, since a tan changes how the skin responds at the next appointment.
Does the tattoo need to be fully removed?
Not always, and saying so early saves people money. If the plan is a cover-up, the artist usually needs the existing ink faded rather than gone, and that is a far shorter course than complete removal. Bring the design you are considering to the consultation, because how much fading is needed depends on what is going over the top.
Why the consultation comes first
Tattoo removal is one of the areas where the assessment does most of the work. The same design in two different people, in two different inks, on two different skin types, will not behave the same way, and the plan should reflect that rather than a standard protocol.
Pulse Light Clinic is CQC-registered and doctor-and-nurse-led, and has been treating patients in London since 2001. A consultation covers what is in your tattoo, which approach suits it, and what can realistically be achieved.
Book a consultation to have your tattoo assessed and a plan explained before any treatment is booked.
