Build a depth map for laser engraving, then calibrate it

A depth map for laser engraving defines which parts of the design are nearer and how the intervals between them are distributed. What the material does with that definition is a separate question answered by power, speed, focus, interval, and pass count. Keeping the two apart is what makes a bad result diagnosable.

When both are guessed at once, an unsatisfactory burn tells you nothing: the image may have been wrong, the settings may have been wrong, or the material may simply not respond as expected. Fix the file first on screen, then vary one machine parameter at a time.

A useful test uses the same material batch, the same lens and focus, and the same interval as the production job. Anything else measures a different setup. Vary one axis at a time so the result can be read: a strip that changes power and speed together produces a range of outcomes with no explanation attached.

Reuse the approved depth field across the whole matrix. Because the image is constant, every difference you observe belongs to the machine or the material, which is exactly the property that makes a calibration sequence worth recording.

Depth and direction say nothing about fumes, fire risk, reflective coatings, or unknown plastics, and no exported file can make an unsafe material safe. Follow the machine manufacturer's guidance, provide extraction, and stay with an operating laser.

Then decide the pass structure from the test rather than from the preview. The preview tells you whether the relief reads; the scrap strip tells you whether this material can produce it at the resolution you designed.