What to know first
- Wood commonly darkens under the laser, so a normal positive image is often the correct starting polarity.
- Species, grain, glue, finish, and moisture can change the result even when the bitmap and machine settings stay fixed.
- Set the final physical size and tested DPI before creating the one-bit dither.
- Use a representative crop on scrap from the same material before engraving the final piece.
Start with what the wood can reproduce
A photo engraving on wood is built from darkened marks against a lighter surface. That makes a normal positive image the usual starting point, but it does not make every pale board behave the same. Species, veneer thickness, grain direction, glue pockets, finish, and moisture can all change darkness and edge spread.
Image preparation controls crop, tone, polarity, dot placement, and pixel dimensions. It cannot predict the exact mark made by a particular laser on a particular board. Treat the prepared file and the material test as two connected stages.
Choose a photo with separation at the final size
Favor a sharp subject, readable edges, and visible separation between the subject and background. A close portrait usually preserves more facial detail than a full-body image when both are reduced to the same coaster or plaque size.
Judge the source near the intended engraving dimensions. Fine hair, distant eyes, textured clothing, and a busy background may collapse into the same narrow band of marks after reduction. Crop away detail that does not help the subject read.
- Use the original photo instead of a screenshot or messaging-app copy.
- Avoid clipped highlights that leave large empty regions in the final pattern.
- Open deep shadows enough to preserve important edges without flattening the image.
- Remove or simplify a background when it competes with the subject.
Protect highlights and separate the midtones
On light wood, darker pixels commonly correspond to stronger visible marks. Keep enough open space for highlights while separating important midtones such as skin, fur, and fabric. If too much of the source sits in a dark middle range, the dither can create a dense field that burns together.
Adjust exposure, gamma, contrast, black point, white point, and sharpening while watching the subject rather than chasing a dramatic screen preview. Excessive sharpening can create halos. Excessive contrast can erase the subtle transitions a photographic dither needs.
Size first, then compare dithers
Physical width and intended DPI determine the pixel grid. Prepare that grid before applying a one-bit dither. Resizing afterward can remove isolated dots, merge neighboring marks, or introduce gray interpolation that triggers another conversion downstream.
Jarvis and Stucki are common photographic starting points in current LightBurn and xTool guidance. Floyd-Steinberg is a useful compact baseline. Compare them on the same crop at the same dimensions rather than changing tone, dither, and size together.
Preserve the finished pixels
If EngravePrep created the final one-bit PNG, import it at the intended physical dimensions and use the destination workflow that preserves externally processed pixels. In LightBurn, that is Pass-Through. Do not apply another photo dither to the prepared file.
Preview closely enough to confirm the expected dots remain. Check polarity, width, height, and line interval before moving to machine settings.
Sources: 4
Test the same wood, not just the same species
Use scrap from the same sheet or batch when possible. Include a highlight, midtone, shadow, fine edge, and patch of background in the test crop. Hold the bitmap fixed while testing focus, interval, speed, and power within the machine maker's safe guidance.
Record the material, finish, lens or module, focus method, interval, speed, power, and date. A saved setting is a repeatable starting point, not a guarantee for the next board.
Common questions
Should I invert a photo for wood laser engraving?
Usually not when the laser creates a dark mark on light wood. Confirm with a polarity strip because painted, coated, stained, or unusually dark wood can behave differently.
Which dither works best for a photo on wood?
Jarvis and Stucki are useful photographic starting points, while Floyd-Steinberg provides a compact baseline. Compare the same final-size crop on the actual wood because no algorithm wins for every photo and process.
Why does my wood photo look too dark?
The source shadows may be compressed, the dither may be too dense, scan lines may overlap, or the process may deliver too much energy. Inspect the exported bitmap first, then test machine variables with that file held constant.
Sources and further reading
Technical claims were checked against current first-party documentation. Product interfaces and guidance can change, so confirm the current documentation for the software and machine you use.
- Image Engraving on CoastersLightBurn User Guide. Checked August 19, 2026.
- Crafting Perfect Laser PhotosxTool Support Center. Checked August 2, 2026.
- How to Set Bitmap ModexTool Support Center. Checked August 19, 2026.
- Image ModeLightBurn User Guide. Checked August 2, 2026.