guide · photo engraving · all machines

How to Engrave a Photo on Wood with a Diode Laser

For photo engraving on basswood with a 10W diode laser, start at 65% power, 2,500 mm/min (42 mm/s), 300 DPI, Jarvis dithering in LightBurn Image mode. The image preparation step matters more than the exact settings — boosting contrast and choosing the right dithering algorithm often makes the difference between a muddy burn and a recognisable portrait. Last verified: 2026-07-02 — lasertinkerer.com

Use dithering, not grayscale — and here's why it matters

This is the most common mistake beginners make in LightBurn, and it costs them hours of troubleshooting. The Image mode menu in LightBurn offers several options: Threshold, Dither, Grayscale, Ordered, Newsprint, and Stucki/Jarvis/Floyd-Steinberg. Only the dithering options (Jarvis, Stucki, Floyd-Steinberg) produce good results on diode lasers.

Here is why grayscale fails on diodes: a diode laser has a minimum threshold — below roughly 5–15% of its rated power, the semiconductor diode doesn't lase reliably. It either fires at full intensity, flickers, or doesn't fire at all. This means the laser cannot smoothly modulate from 0% to 100% the way a CO2 or fiber laser can. Grayscale mode in LightBurn assumes the laser can produce varying intensities proportional to pixel brightness — on a diode, this assumption breaks. You get muddy mid-tones and bright highlights that all burn at the same intensity.

Dithering sidesteps this entirely. The laser fires at either 100% or 0% at each dot. Tonal range is created through dot density — a dark shadow area has many dots close together; a bright highlight area has very few dots. The laser never has to modulate power mid-burn. This is why dithering produces photorealistic results on diodes while grayscale rarely does.

Image preparation: this step matters more than the laser settings

A well-prepared image on imperfect settings usually looks better than a poorly-prepared image on perfect settings. The laser engraves exactly what you give it — so give it a high-contrast black-and-white conversion with clear shadow and highlight separation.

Step 1: Choose the right photo

High-contrast subjects work best: sharp shadows under a chin, defined cheekbones, bold outlines. Soft studio lighting with graduated shadows produces better results than hard midday sun or flat indoor light. Avoid photos where the important detail is in the shadows — the laser burns shadows black and can't restore detail that isn't there in the source image.

Step 2: Convert to grayscale with a channel mix

Don't just desaturate. In Photoshop or GIMP, use a Channel Mixer or Black & White adjustment layer. Dragging the Red channel higher brightens skin tones and separates facial features from backgrounds. A typical starting mix for portraits: Red +60, Green +30, Blue +10. (The numbers should sum to 100%. Adjust to taste on your specific image.)

Step 3: Boost contrast and darken

Increase contrast by about 10–20% and reduce overall brightness by 10–15%. This counteracts the laser's tendency to lose highlight detail — when a pixel is very bright, the dithering algorithm places almost no dots, and those near-white areas can look washed out compared to the original. Darkening the image slightly ensures highlights still have enough dots to register.

Step 4: Set image resolution to 300 DPI before importing

Set your source image to 300 DPI before importing it into LightBurn. This avoids LightBurn having to resample the image up or down. Import at the final physical size — if you're burning a 100 × 100 mm tile, your image should be 100 × 100 mm at 300 DPI (which means 1181 × 1181 pixels). Your DPI settings guide has the full spot-size formula.

Step 5: Test, then burn

Run a small 30 × 30 mm test strip on scrap from the same material batch, at the same power and speed as your final burn. The test strip takes a few minutes and saves a ruined piece. The material test grid generator lets you scan a range of powers and speeds automatically.

Which wood works best for photo engraving?

The two things that ruin a photo engraving are grain interference (the wood's own texture overwhelms fine image detail) and low contrast (the burned marks don't stand out against the wood's background colour). These two criteria point to different materials.

Laser settings for photo engraving by wattage

These settings produce tonal photo engravings using Jarvis dithering at 300 DPI. They are starting points — always run a test strip on scrap from the same batch. The 10W row has two independent sources; other rows are estimated from the Laser Tinkerer Energy Index scaling model and are labelled accordingly.

All four machines benefit from the same DPI (300–318) because DPI controls physical dot spacing, which is about focus spot size, not laser power. The focus spot on a 5W and a 40W diode of the same generation is similar. See the DPI settings guide for the spot-size formula.

Dithering algorithms in LightBurn: which one to choose

Step-by-step LightBurn workflow

Here is the full LightBurn workflow from image import to job start:

1. Focus the laser first. Even 0.5 mm out of focus softens dot edges and makes detail merge. Use your machine's focus gauge or the ramp test method. See the focus guide.
2. Import your image into LightBurn (File → Import, or drag and drop). Right-click it and choose "Adjust Image" to see the brightness/contrast controls.
3. Set power and speed on the Cut/Layer panel. The layer mode should be "Image" — if it shows "Fill" or "Line", right-click the layer and change it to Image.
4. Open Image Settings (double-click the image on the canvas). Set:
   • Mode: Jarvis (or Stucki)
   • DPI: 300 (or the value from the DPI guide)
   • Brightness: −10 to −20
   • Contrast: +10 to +20
   • Gamma: leave at 1.0 to start; reduce (0.8) to brighten mid-tones if they engrave too dark
5. Set air assist to low if your machine has a controllable pump. LightBurn assigns air assist per layer — keep it OFF or at minimum for the Image layer.
6. Run a frame pass (Frame button, or Shift+F) to verify the job boundaries without firing the laser.
7. Burn a test strip on scrap — cut a 30 × 30 mm section of your image and burn it first. Adjust brightness/contrast in the Image Settings panel based on the result, not by changing power or speed (power and speed control the depth of the burn; brightness/contrast control the tonal mapping).
8. Run the full job at the tested settings.

Common problems and fixes

Advanced techniques

Baking soda wash for higher contrast

Brushing a diluted baking soda solution onto the wood surface before engraving increases the alkalinity of the wood fibres. The laser's heat reacts more strongly with an alkaline surface, producing darker burns with the same energy input. Mix about 1 teaspoon of baking soda into 250 ml (1 cup) of water, brush onto the wood evenly, and let it dry completely before burning. Reduce power by about 10% compared to untreated wood — the reaction does some of the work. Source: community technique reported on atomm.com.

Two-pass engraving for depth

Run the same image twice at lower power. First pass at about 55% power, 3,000 mm/min; second pass at 45% power, 3,500 mm/min. The combined energy builds depth in shadow areas while lighter areas, which receive fewer dots from the dithering algorithm, avoid double-burning the highlights. This technique can improve tonal separation on woods where a single pass produces flat-looking results.

White-paint-first on dark woods

For walnut, dark cherry, or other woods where burned marks don't contrast against the natural background: apply a thin, even coat of flat white paint, let it dry, then engrave. The laser burns through the paint into the wood in shadow areas, revealing the dark wood beneath. Highlights stay white. The result is a high-contrast image with a distinctive two-tone effect. Use standard acrylic craft paint; nothing special required. Wipe the surface with a damp cloth immediately after engraving to clean residual paint dust from the unburned areas.

Red-channel conversion in Photoshop/GIMP

Standard desaturation (Image → Grayscale in most editors) weights channels equally. For portraits, the red channel conversion preserves facial skin tones as lighter grays (which the laser won't over-burn) and converts dark hair and eye colours to correctly dark tones. In LightBurn's Image Settings, the "Passthrough" mode lets you feed a pre-processed grayscale image directly without LightBurn applying any additional conversion. Use this when you have prepared the image in an external editor and don't want LightBurn's brightness/contrast adjustments to interfere.

Safety for photo engraving sessions

Photo engraving runs are typically long — a 150 × 150 mm portrait at 300 DPI takes 30–60 minutes. During that time the laser is producing smoke continuously. Ensure:

• Ventilation: exhaust to outside or use a fume extractor rated for laser use. Wood smoke is not benign — it contains fine particulates and VOCs.
• OD7+ safety glasses rated for 450 nm wavelength — the laser is on at regular intervals throughout a long raster job. Never rely on just watching the machine.
• Don't leave a long job unattended — the material bed is covered in fine char dust by the end of a photo engrave, and a stray ember can start a fire.
• Air assist at low pressure protects the lens from char build-up during a long engraving run. Clean the lens before long jobs.

Frequently asked questions

What are the best LightBurn settings for photo engraving on wood?

For a 10W diode laser on basswood: 60–70% power, 2,500–3,000 mm/min (42–50 mm/s), 300 DPI, Jarvis dithering in LightBurn Image mode. These two settings come from craftgineer.com and atomm.com, which are the two most consistently cited community sources for diode laser photo engraving. Always confirm on a test strip before the final burn.

Should I use dithering or grayscale mode for photo engraving?

Use dithering. Diode lasers have a minimum power threshold — they fire at full intensity or not at all below roughly 5–15% of rated power. Grayscale mode assumes the laser can modulate smoothly, which diodes can't reliably do. Dithering turns the laser on or off at each dot; tonal range comes from dot density. This is why dithering produces photorealistic results while grayscale often produces flat or banded marks on diode lasers.

Which dithering algorithm is best for photos in LightBurn?

Jarvis gives the most photorealistic results for most photos on wood. Stucki is a close second. Floyd-Steinberg is faster to compute but can produce faint horizontal banding in uniform mid-tone areas. Ordered and Newsprint are artistic effects, not photorealistic modes. Start with Jarvis for portraits and switch to Stucki if you see any patterning artefacts.

What wood is best for laser photo engraving?

Basswood and maple are the best choices — both have tight, uniform grain that doesn't compete with fine image detail, and their light natural colour produces high contrast against the burned marks. Birch plywood (laser-grade) is a good budget option. Avoid walnut for direct photo engraving because the dark background produces very low contrast — unless you apply the white-paint-first technique described above.

Why does my laser photo look burned or blurry?

The most common cause is too much energy — power too high or speed too slow. Reduce power by 5–10% or increase speed by 20% and run a test strip on scrap. The second most common cause is focus: even 0.5 mm out of focus softens dot edges and makes fine detail merge together. Always check focus first, then adjust energy. The focus guide covers the ramp test method.