Photo Prep for Laser

Most disappointing photo engravings fail before the laser ever fires. Contrast, dithering choice, and resolution decide whether a face reads at arm’s length, and the right answer changes with the material. This hub runs from raw photo to a file that burns predictably.

Resolve the photograph before converting it

Choose a sharp source with a readable subject and crop for the finished blank. Use background removal when the surroundings distract from the engraving, and upscale before dithering when the source needs additional pixels. Inspect the result for missing edges or altered details before continuing.

Set physical size before judging the dots

In Photo Prep, enter the intended dimensions and DPI, then use the closest material preset as a starting point. Compare tonal balance and dithering algorithms at that output size. Preserve useful highlights and shadows instead of judging contrast from a small, resized thumbnail.

Carry the prepared image through import

Export the prepared image or supported native format and confirm dimensions in the receiving laser software. Check its image mode so an already prepared dot pattern is not unintentionally dithered again. Test a small crop containing both light and dark detail on the actual material before engraving the full photograph.

Choose a dithering family for the look you want

Image Lab photo prep has 15 algorithms in four families. Error diffusion (Floyd-Steinberg, Jarvis-Judice-Ninke, Stucki, Atkinson, Sierra) gives the most photographic result. Halftone screens (round, line or diamond dots, with dot size and screen angle) look like print. Bayer ordered grids at 2x2, 4x4 or 8x8 give a regular, graphic pattern. Plain threshold suits logos and text. Each card previews your own photo at the size and DPI you chose.

Match the preset to how the material marks

Wood darkens where the laser hits, so a photo burns as it is. Slate and black-painted stone mark lighter than the surface, so their presets invert the photo. White tile does not mark by itself: spray it black, burn, then wash off the unburned paint. The free photo dithering page bundles those four starting points (Wood at 254 DPI with Jarvis-Judice-Ninke, Slate and Tile at 300 DPI with Stucki, Painted stone at 254 DPI with Atkinson).

Set DPI from your spot size, then match the interval

More DPI is not always sharper: once the dots are smaller than the burn spot they merge into dark patches. Pale, tight-grained wood such as basswood or maple holds detail around 254 DPI; slate and tile tolerate 300. Whatever you pick, set the same value as the line interval in your laser software: 25.4 divided by the DPI gives millimetres, so 254 DPI is a 0.1 mm interval.

Prep a batch without uploading it

Photo prep and dithering run in your browser and cost nothing, so customer photos are not uploaded for this step. Batch Mode processes many photos at once, which helps when a run of memorial plaques or pet coasters has to look consistent. Only the optional AI steps, such as upscaling, background removal or vectorizing, use credits, and each shows its cost before it runs.

Know when a photo should not be dithered

Dithering is for flat raster engraving. If the job is a carved relief, make a 16-bit depth map in Depth Studio instead, so the laser or CNC varies depth rather than dot density. If the subject is line art, a logo or lettering, vectorize it to clean SVG paths. And if the photo is soft, small or noisy, upscale or clean it first: dithering preserves every flaw it is given.