How to turn a photo into a laser engraving (wood, metal and more)

Engraving a photo isn't the same as engraving a logo or text. A vector gets cut or marked as-is; a photograph has to go through a process that turns it into something the laser can actually reproduce. Skipping that process is the number one reason a portrait comes out as a grey, detail-less blob.

Why you can't engrave a photo directly

On the vast majority of hobby machines (diode and CO₂ engraving lasers), the laser only has two states per point: burn or don't burn. There are no 256 physical shades of grey like on a screen. To simulate those tones, the software scatters burned and unburned points in a pattern the eye blends from a distance — that's dithering, and it's the step that actually turns a photo into an engraving.

If you upload a photo straight to LightBurn in grayscale mode without dithering, some machines interpret it by modulating laser power instead of dot density. It works, but gives flatter, less defined results compared to good dithering — especially on wood and anodized aluminum.

The full workflow, step by step

1. Pick a photo that will actually work

Not every photo engraves well. The ones that turn out best have:

• Good contrast between subject and background. A flat, overexposed photo loses the subject in the dithering.
• A defined subject, ideally with a blurred or simple background. Detailed backgrounds (foliage, crowds) turn into noise.
• Enough real resolution. A compressed WhatsApp photo stretched to double its size doesn't gain detail, just JPEG blocks that dithering will exaggerate.

2. Crop and frame before dithering

Crop first, dither second — never the other way around. If you crop after dithering, the dot pattern ends up misaligned with the new edges and looks inconsistent at the corners.

3. Pick the dithering algorithm based on the image

There's no universal dithering choice. Floyd-Steinberg is a reasonable starting point for almost everything; Atkinson smooths portraits better; Stucki brings out fine detail more. The difference is real and visible to the naked eye.

I cover this with examples and a full table in which dithering algorithm to choose for laser engraving.

4. Set the output resolution (DPI)

DPI determines how many dithering lines fit per inch — more DPI means more detail, but a lot more machine time and more heat buildup in the material. Every machine and material has a range that actually makes sense; using 1200 DPI on a diode over MDF just burns the material without adding anything.

Full table by material and laser type in what DPI to use for laser engraving.

5. Pick the material — they don't all behave the same

• Wood (MDF, plywood): dithering shows up as real burn texture. It's more forgiving of contrast mistakes because wood already has its own background tone.
• Anodized aluminum: the laser doesn't engrave depth — it burns off the anodized layer and exposes the bare aluminum underneath. Contrast is extremely high (nearly pure black and white), so dithering needs to be well calibrated or a portrait ends up looking "blown out" in the light areas. Full detail in laser engraving on anodized aluminum.
• Stainless steel: similar binary behavior to aluminum, but needs more power and often requires marking spray on diode lasers to darken the mark.
• Acrylic: the engraving looks like a frosted surface; contrast tends to be softer than on metal.

6. Set power and speed once the file is dithered

Once you have the file dithered at the right resolution, what's left is the physical part: power, speed and passes for your machine and material. That part doesn't depend on the photo — it depends on your laser's calibration, which I cover in power and speed settings by material.

Common mistakes when turning a photo into an engraving

Uploading a low-resolution photo and expecting detail. Dithering doesn't invent information that isn't in the original. If the source photo is 400×400 px, a 10×10 cm engraving at 300 DPI won't have more detail than the photo already had.

Not adjusting contrast before dithering. Photos taken in low light or that are too flat need a contrast (and sometimes brightness) boost before dithering — doing it afterward, on the already-dithered result, doesn't work as well.

Using the same algorithm for everything. A logo with text needs different dithering than a portrait. Testing 2-3 combinations on a small scrap before committing the good material saves wasted pieces.

Ignoring the background. A background with texture or crowds gets dithered the same as the subject and visually competes with it. Cropping the background out (or blurring it beforehand) improves the result more than any dithering tweak.

Doing it without processing the image by hand

This entire workflow — dithering by algorithm, DPI control, presets calibrated by material and laser type — is exactly what MEZ Laser does in your browser, for free: upload the photo, pick the material and algorithm, and download a file ready for your machine.