Affinity Photo (Affinity by Canva) for Laser Engraving: Grayscale, Contrast, and Dithering Prep

Affinity Photo used to be a standalone, one-time-purchase app — but Canva acquired Affinity and relaunched it as a single, free, unified application ("Affinity by Canva") that merges what used to be three separate apps (Photo, Designer, Publisher) into one program with three switchable "Studios." Everything in this guide is the Pixel Studio — same tools, same workflow, just inside the unified free app rather than a standalone Photo install. It's genuinely well-suited to the specific image prep laser engraving needs — real grayscale/levels control, proper dithering options, and non-destructive editing that lets you iterate on settings without repeatedly starting from the original file. This covers the actual workflow: turning a normal photo into something that engraves well, not just generic photo editing.

Why Photo Prep Matters So Much for Engraving

A laser can't reproduce a full-color photograph directly — it's working in whatever the engrave mode actually does (typically grayscale power modulation or dithered black/white), and an image that looks great on a screen often engraves as a muddy, low-contrast mess without the right prep. Getting this right in software, before ever sending a file to the laser, saves an enormous amount of wasted material and time compared to iterating via test burns alone.

Step 1: Convert to Grayscale Properly

Document → Convert Format/ICC Profile → Grayscale — this is a genuine conversion, not just desaturating, and gives you a true single-channel image to work with
Avoid just reducing Saturation to zero — this leaves the file in RGB mode with equal-but-still-three channels, which can behave unpredictably when your laser software reads brightness values; a real grayscale conversion is cleaner
Check the result against the original — some colors that look very different to the eye (certain reds and greens especially) can convert to very similar gray values, flattening detail that mattered in the original photo; if this happens, going back and adjusting individual color channels BEFORE conversion (see Step 2) helps preserve that separation

Step 2: Adjust Levels and Curves Before Committing

This is the step most people skip, and it's the single biggest factor in whether a photo engraves with real depth or looks flat:

Open the Levels adjustment (Layer → New Adjustment Layer → Levels) — pull the black and white point sliders inward until they just touch the actual histogram data, which immediately increases usable contrast range
Use Curves for finer control — an S-curve (darkening shadows slightly, brightening highlights slightly) generally makes engraved photos read with more apparent depth, since it exaggerates the tonal separation the laser will actually be able to express
Keep adjustments non-destructive — using adjustment layers (not directly editing pixels) means you can go back and refine after seeing a test engrave, without starting over from the original photo

Step 3: Sharpen for the Loss You're About to Introduce

Dithering and low-resolution engraving both throw away fine detail — a bit of extra sharpening beforehand compensates:

Filters → Sharpen → Unsharp Mask, applied more aggressively than would look right for on-screen viewing — the dithering step coming next will soften the result, so slightly over-sharpening here is correct, not a mistake
Check at 100% zoom, not fit-to-screen — sharpening artifacts that are invisible when zoomed out become obvious at native resolution, which is closer to how the laser will actually "see" the pixel data

Step 4: Dithering — The Actual Engrave-Readiness Step

Most laser software (LightBurn, LaserBurn) has its own dithering options built into the image import settings, and for most workflows, that's the right place to do it — the software knows your specific laser's actual dot/power characteristics better than a generic image editor does. The site's own Laser Image Prep tool can also help sanity-check grayscale, contrast, and dithering settings quickly without opening a full editor. But Affinity Photo is useful for previewing what different dithering approaches will look like before committing:

Document → Convert Format → Grayscale should already be done at this point (Step 1)
Use the Posterize adjustment to preview a reduced-tone-count version — this approximates (roughly) what your laser's engrave mode will do, giving you a sense of whether the image will hold up at lower fidelity before you actually burn material
If your laser software's dithering options are limited, some workflows do final dithering in Affinity Photo itself (there are third-party dithering personas/plugins, or manual Halftone filter use) and export a pre-dithered bitmap directly — this trades flexibility for more control over exactly how the dither pattern looks

Step 5: Crop, Resize, and Set Real-World Dimensions

Set the document size to your actual target engrave dimensions before final export — Document → Resize Document, matching real-world units (mm/inches) to what your laser software expects, at your laser's working resolution (matching the DPI your laser software uses for image imports, commonly around 254-500 DPI depending on the machine)
Resample using an appropriate method — Bicubic is a reasonable general default for photo resizing; avoid Nearest Neighbor for photos specifically (that's more appropriate for pixel art or line work)
Crop tightly to the actual subject — excess blank border wastes material area and adds engrave time for nothing

Practical Workflow Summary

Import/open the source photo
Convert to true grayscale (Document → Convert Format)
Adjust Levels/Curves for contrast (non-destructive adjustment layers)
Sharpen more than looks natural on-screen
Preview posterization/dithering to sanity-check tonal range survives
Resize to real-world target dimensions at correct DPI
Export as PNG (lossless) or high-quality JPEG for import into your laser software

Export Settings That Matter

FormatWhen to UseNotes PNGDefault choice for engrave prepLossless, preserves exact pixel values — no compression artifacts to confuse the laser software's dithering TIFFIf your laser software specifically prefers itAlso lossless, larger file size, less universally supported than PNG JPEGOnly if file size is a genuine constraintLossy compression can introduce subtle artifacts that show up as noise in the engrave — avoid unless necessary

Common Problems and Fixes

"The engrave looks flat/low-contrast" — almost always a Levels/Curves issue; go back and check the black/white points are actually touching the histogram data, not just centered by default
"Fine detail is lost/muddy" — likely needs more aggressive sharpening before dithering, or the source photo's resolution genuinely isn't high enough for the target engrave size
"Dithering pattern looks like visible noise instead of smooth gradients" — this is often a laser-software-side dithering ALGORITHM choice (try a different dither mode there) rather than something to fix in Affinity Photo itself

The core insight worth remembering: a photo that looks correct on a calibrated monitor is optimized for a completely different output medium than a laser burning material — the prep work here exists specifically to bridge that gap, not to make the image "look better" in the abstract.

See the Affinity by Canva overview for the bigger picture on the unified app, or real project scenarios combining Pixel Studio work like this with Vector and Layout Studio.

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