In Part 1 you learned why stainless steel takes colour, and in Part 2 you learned what the four parameters do. This part is where it all comes together — you'll open LightBurn, configure colour layers, run a test card to verify your results, and engrave your first real piece.
There are two paths to get set up. The fast path uses a pre-configured file from MOPA Color Studio. The manual path walks you through entering settings yourself. Both end at the same place.
Understanding LightBurn's layer structure for colour work
LightBurn organises everything you engrave into numbered layers, each shown as a coloured square in the Cuts / Layers panel. For MOPA colour work, the key rule is simple: one colour = one layer. Each colour in your design needs its own layer because each colour requires completely different parameter settings.
Each numbered layer holds one colour's complete parameter set. LightBurn fires them in order — darker colours first, lighter colours last.
MOPA Color Studio manages this structure for you — it organises up to 28 colour layers (00–27) plus tool layers for metadata and auxiliary geometry. But understanding the structure means you can also build or adjust layers manually when needed.
Configuring a layer manually
If you're entering settings by hand rather than importing a pre-configured file, here's the exact process in LightBurn for each colour layer.
Select the shape or fill in your design that should be one colour. In the Cuts / Layers panel, click an empty layer square to assign it. Give the layer a descriptive name (double-click the layer name) so you know which colour it holds.
Double-click the layer square in the Cuts / Layers panel to open the Cut Settings Editor. This is where all parameters live. Make sure the mode is set to Fill for colour marking — not Line or Offset Fill.
Set the frequency (kHz) and Q-pulse width (ns) for your chosen colour. These are the hue controllers from Part 2 — use the values from your reference chart or the MOPA Colour Reference Chart. If your target colour doesn't specify a pulse width, leave it at the laser's default.
Frequency: 300 kHz
Q-pulse width: 5 ns
Enter the scan speed (mm/s) and line interval (mm). Line interval controls how close together the fill lines are — tighter intervals mean more overlap, more energy per area, richer colour. Most colour recipes use 0.001–0.005 mm.
Speed: 350 mm/s
Line interval: 0.001 mm
Enter your scaled power percentages. Remember: if your recipe is calibrated for 30W and you have a 60W machine, halve the power percentages. LightBurn uses separate Min Power and Max Power fields — both matter for colour consistency at the start and end of each fill line.
Min power: 17% (= 34% × 30 ÷ 60)
Max power: 48% (= 95% × 30 ÷ 60)
In the Cuts / Layers panel, drag layers into the correct firing order. Darker colours (black, dark grey) should fire first; lighter, more delicate colours (gold, light blue, green) should fire last. This prevents thermal bleed from earlier passes affecting areas not yet engraved.
Running your first test card
Before committing any recipe to a real piece, always run a test card. A test card is a small engraved sample — typically on a pre-cut stainless steel business card blank — that shows you exactly how your machine produces each colour under your actual conditions.
The MOPA Colour Reference Chart provides ready-to-use test card files for 20W, 30W, 60W, and 100W machines. Each file has all 15 colour swatches pre-laid-out on a 88.9 × 50.8 mm card, numbered and colour-coded. Download the file for your wattage, open it in LightBurn, position your blank under the frame outline, and run it.
When the test card is done, compare each numbered swatch to the recipe in the reference chart. If a colour is close but not quite right, that's your baseline for adjustment — you know which direction to nudge the parameters, rather than starting from scratch.
Troubleshooting common results
Your test card results will tell you a lot. Here are the most common symptoms and what they usually mean.
| What you see | Likely cause | Try this |
|---|---|---|
| No colour — just a grey or white mark | Power too high, speed too low, or wrong laser mode | Reduce power by 10–15%. Check you're in Fill mode, not Line. Verify frequency and pulse width are set correctly. |
| Colour is very faint or barely visible | Power too low, speed too high, or focus off | Increase power slightly. Reduce speed by 10%. Check Z-height and re-focus. |
| Colour is uneven or patchy across the swatch | Surface contamination, inconsistent polish, or focus variation | Clean the surface with IPA and try again. Check the blank is flat and secured. Re-verify focus at multiple points. |
| Wrong colour — blue looks purple, gold looks red | Frequency or pulse width entered incorrectly | Double-check values against the reference chart. A small frequency error shifts the colour significantly. |
| Colour visible but muddy or brown-tinged | Surface oxidising too aggressively — power too high | Reduce power by 5–10% and re-run. Also check steel grade — some grades are more sensitive. |
| Lines visible in the fill — striped appearance | Line interval too large | Reduce line interval (try 0.001 mm). Ensure Fill mode is selected, not a line-based mode. |
From test card to finished piece
Once your test card confirms a colour is behaving as expected, you're ready to use that layer recipe on a real design. The workflow from here is the same as any LightBurn job — place your artwork, assign shapes to the correct colour layers, frame the job, and run it.
A few things worth keeping in mind as you move from test card to production:
Large filled areas take longer and build up more heat than small swatches. If your full-size design shows colour shift compared to the test swatch, try reducing power slightly or increasing speed to compensate for the longer cumulative exposure.
Save your working layer settings as a LightBurn library entry once you've dialled in a colour on your machine. That way you don't have to re-enter parameters every time — you load the library, drag the setting onto the layer, and you're done.
It's also worth keeping a handwritten record of your verified settings — colour name, frequency, pulse width, speed, power, line interval, and which steel grade and surface finish they were tested on. A small notebook or even an index card taped inside a cupboard door takes thirty seconds to fill in and has saved more than a few jobs when a LightBurn file went missing, a computer was replaced, or a library entry got overwritten. Digital backups are convenient right up until they aren't.
Series complete — you're ready to engrave
You've covered the science, the parameters, and the workflow. The best next step is to download a test card file, grab a stainless blank, and run your first colour job.
Frequently asked questions
How many layers does a typical MOPA colour job use in LightBurn?
Each colour in your design needs its own layer, since each colour requires different parameter settings. A simple two-colour piece uses two layers. A complex multi-colour design might use six or more. MOPA Color Studio manages up to 28 colour layers plus two tool layers and two auxiliary layers.
What order should layers fire in for MOPA colour marking?
Fire darker colours first and lighter colours last. Black and dark greys should run before blues, golds, and greens. This prevents earlier passes from thermally affecting areas that haven't been engraved yet. The exact order matters most when colour areas are close together or overlapping.
Can I import my MOPA Color Studio settings directly into LightBurn?
Yes. MOPA Color Studio exports a .lbrn file with all layer settings pre-configured. Open it in LightBurn, place your artwork on the appropriate layers, and the parameters are already set. You can also import individual layer settings using LightBurn's cut settings import feature.
Why does my test card show inconsistent colour across the swatch?
Uneven colour across a swatch usually points to one of three causes: inconsistent surface finish (check for fingerprints, scratches, or uneven polish), focus or Z-height issues (the beam may not be perfectly focused across the whole swatch), or the material shifting during the job. Clean the surface with IPA, re-verify focus, and ensure the blank is secured flat before re-running.