3D laser engraving builds depth by converting a grayscale image into varying laser power, carving each tone at a different height.
3D engraving doesn’t need a different machine or a magic button. The same raster laser that burns a photo into wood can carve a shallow relief: you feed it a grayscale image, and it varies the laser’s power (sometimes focus) tone by tone. Here’s how to do 3D laser engraving without the guesswork, from image prep to safety.
How 3D Engraving Creates Depth
3D laser engraving creates depth by mapping brightness to cutting intensity. White or black becomes the highest point, the opposite tone cuts deepest, and the grays between them become the slope. That’s why the starting image matters more than the wattage.
In that workflow, black controls the 3D raster power settings.
3D Laser Engraving Settings That Actually Matter
The fastest route to a sharp relief is to treat the job as a raster print, not a vector cut. Import the grayscale image as a grayscale engraving layer instead of dithering it, so the software can vary power across the surface. That layer choice separates true depth from a flat photo burn.
Work through these steps in order:
- Convert the image to grayscale and boost contrast so the height map has smooth transitions. Decide whether white or black will be the highest point before changing anything else.
- Import it into LightBurn or similar software and set the job to raster or 3D engraving mode, not vector mode.
- Set scale to 1:1 and confirm the image size matches the material.
- Choose a line interval for detail.
- Set power and speed for your material, then focus the laser carefully.
- Frame the work area, secure the material flat, and monitor the first minutes of the run.
If your software only offers dithering, you can still engrave a grayscale image at a low line interval, but the relief comes out flatter. A true grayscale mode maps power continuously; dithering breaks the image into dots that the laser burns more evenly.
Laser Types, Materials, and Safety
Matching the laser to the material is as important as matching the image to the software. Diode lasers are the usual choice for wood and acrylic relief, fiber or MOPA lasers handle metal, and UV lasers are better for 3D effects inside glass.
If you’re choosing a machine and want real-world comparisons before spending money, our tested roundup of 3D laser carving machines is worth reading first.
Safety is the part most tutorials gloss over. The material table below covers the rest.
| Material or Laser | What Works | Watch Out For |
|---|---|---|
| Wood and acrylic relief | Diode laser, secured flat, with air assist | Smoke and residue between passes |
| Metal | Fiber or MOPA laser | Best for marking and metal 3D effects |
| Inside-glass 3D | UV laser | Fragile surfaces and crack risk |
| Mirrored materials | Avoid | Reflection can scatter the beam |
| PVC and vinyl | Avoid without extraction | Can release chlorine gas |
| Leather and artificial leather | Ventilate and wear protection | Can release chlorine gas |
| Coated carbon fiber | Use ventilation and protective gear | Produces harmful gases |
Run a small test tile before the final piece — engrave a small swatch at three power levels, check the depth, then commit. No matter what you engrave, keep the job in sight from start to finish. Once you find the power, speed, and line interval that works for a material, write it down; a successful 3D relief is simply a good grayscale image respected by consistent settings.
FAQs
What kind of laser do you need for 3D engraving?
Most raster-capable diode and fiber lasers can produce shallow relief if the software has a grayscale or 3D mode. True sculpted depth with variable Z movement needs a three-axis system, such as EZCAD3-compatible hardware. For most hobbyists, a diode laser on wood or acrylic is the easiest place to start.
Which image format works best for 3D laser engraving?
A high-contrast grayscale PNG or JPEG works, and a proper depth map is even better because it encodes height as brightness. Avoid dithered images, busy backgrounds, and heavy noise, since the laser follows every tone. Boost contrast slightly before importing it into your software.
References & Sources
- Harvard Graduate School of Design Fab Lab. “3D Laser Engraving.” Documents the raster workflow, image density 6, and 1000 PPI setting used in this article.