⚠️ Always test on scrap first. Wattage scaling gives you a starting point — your specific machine calibration, lens, and material grade will require small adjustments. Never mark a final piece without a test run.
Why only power scales — and what that means for you
MOPA colour marking parameters are often shared online without the wattage context, which causes confusion when you try to use a 60W recipe on a 30W machine. The results look wrong because the energy delivery is wrong.
Power percentage is the lever that compensates for wattage difference. If a 60W machine delivers the right colour at 40% power, your 30W machine needs roughly 80% power to deliver the same total energy to the surface — because it's working with half the raw wattage.
Speed, frequency, and pulse width are about the effect, not the machine's power level. Speed controls how long the beam dwells on each point. Frequency controls how many pulses hit the surface per second. Pulse width shapes the energy profile of each individual pulse. None of these need to change just because you've moved to a different wattage machine — the oxide layer physics is the same regardless of whether the source is 30W or 100W.
The exception is if you're hitting the limits of a lower-wattage machine — for example, running a 20W machine at 100% to match a recipe that scaled to 110% (impossible). In those cases, you may need to slow the speed slightly to compensate for the power ceiling, which increases dwell time and makes up some of the energy deficit. The tool flags this situation and explains it when it happens.
Questions
4 questionsWhy don't frequency and pulse width need to change between wattages?
Frequency and pulse width are parameters that define the character of the laser pulse — how many pulses per second hit the surface, and how much energy each individual pulse carries. These determine which oxide layer thickness you're targeting, which is what produces a specific colour. That relationship between pulse shape and oxide layer is a physics property of stainless steel (or titanium, or whatever you're marking), not of your machine's power rating.
Put simply: a 200kHz frequency with a 6ns pulse width targets the same oxide layer whether the machine is 30W or 100W. What changes is how hard the machine has to work (power %) to deliver enough energy to actually grow that layer.
What if the scaled power comes out above 100%?
That means the source recipe was calibrated for a significantly more powerful machine than your target. Your target machine physically can't deliver enough power at 100% to match the original. The tool caps the result at 100% and flags the situation.
In practice, your options are: increase the number of passes (multiple passes add up total energy), slow the speed slightly to increase dwell time and energy per point, or accept that some colours may not be fully achievable at your machine's wattage. Very deep reds and some bright golds tend to need more power, and they're the first to suffer when you're scaling down significantly.
Is this tool accurate enough to skip test runs?
No — and it's important to be honest about that. The scaler gives you a mathematically sound starting point, but real-world colour marking is affected by variables this tool can't know: your specific machine's actual output efficiency (which may not be exactly rated wattage), lens focal length, material grade and surface finish, and how well the machine is calibrated. Use the output as a first approximation, then run a test grid on scrap stainless before marking anything that matters.
Where can I find verified starting parameters to scale from?
The MOPA Colour Reference Chart here on this site has 15 verified colour recipes for stainless steel, with parameters already scaled for 20W, 30W, 60W, and 100W machines. If you want to go the other direction — adapting a community recipe you found online — this Wattage Scaler is the right tool for that job.