How to print a lithophane (settings & filament)

To print a lithophane cleanly, use a fine layer height (around 0.1 mm), 100% infill so no light leaks through, and print it standing upright so the layer lines run across the image. Stick to white or natural PLA, slow the print down a little, and turn cooling on. Get those right and a flat grey plate turns into a sharp photo the moment you backlight it. Here's the full recipe, plus the model settings that decide how the image reads.

How a lithophane actually works

A lithophane is a thin relief where thickness controls brightness: thick areas block light and read dark, thin areas let light through and read light. There's no ink and no color — the whole image is height. That's why print quality matters so much: every layer line and gap becomes part of the picture when light shines through it.

The model settings that matter

Before you slice, get the model right in the lithophane generator. Three settings shape how the photo reads:

• Max thickness (dark) — how thick the darkest areas get, typically around 3 mm. Thicker deepens the darks but needs a stronger backlight to punch through.
• Min thickness (light) — the brightest areas, kept around 0.8 mm and never below ~0.6 mm so the layer actually prints and still passes light.
• Contrast and Brightness — spread the tones apart and shift the whole image lighter or darker. Bump contrast a little for photos that look flat; ease brightness up if a dark photo prints too heavy.

Pick a Width that suits your frame or lamp, add the optional raised border if you want a finished edge, and export the STL.

Slicer settings for a clean lithophane

Layer height — go fine

This is the single biggest quality lever. Use 0.08–0.12 mm; 0.1 mm is a great all-round choice. Finer layers mean smoother tonal gradients and less visible banding across the image. A coarse 0.2 mm layer height will show obvious steps once it's lit.

Infill — 100%

Print it solid, at 100% infill. A lithophane is thin, and any internal gaps or sparse infill show up as blotches when backlit. Solid also makes the thickness-to-brightness relationship accurate, so the image looks the way it did on screen.

Orientation — stand it upright

For a flat lithophane, print it vertically, standing on its edge. This runs the layer lines horizontally across the image, which reads as natural detail rather than distracting print artifacts, and it captures the fine thickness changes far better than printing flat on the bed. A tall, thin part can be tippy, so add a brim for a solid first-layer grip. (Curved and cylindrical lithophanes are their own shape, but the same fine-layer, solid, slow rules apply.)

Speed and cooling

Slow down to roughly 30–40 mm/s — quality beats speed here, and steady flow keeps the thin walls even. Keep part cooling on so each thin layer sets before the next one lands. No supports are needed for a flat vertical plate.

Walls and line width

Because the plate is thin, the perimeters largely are the print, so accurate walls matter. The default 0.4 mm line width is fine; dropping to ~0.3 mm can sharpen very fine detail at the cost of print time. Enough wall loops plus 100% infill guarantees no thin, translucent weak spots.

Filament: white or natural PLA

White or natural (uncolored) PLA is the classic, and for good reason — it diffuses light evenly and gives neutral, warm tones with strong contrast. PLA prints crisply at fine layers, which is exactly what a lithophane needs.

• Avoid dark or strongly colored filament — it blocks or tints the light and kills the image.
• Skip silk and glitter filaments; their finish scatters light unevenly.
• Grey or light tan can give a slightly moodier look, but white/natural is the safe starting point.

Backlighting it

A lithophane looks like a plain grey plate until light passes through it. Use an even, diffuse light source behind it — an LED panel, a lightbox, a window, or a phone screen for a quick test. A bright, even backlight brings out the darks; a dim one makes the image look muddy. Warm-white LEDs flatter portraits; cool-white gives crisper contrast.

Quick-reference recipe

• Layer height: 0.08–0.12 mm (0.1 is ideal)
• Infill: 100%
• Orientation: vertical, on edge, with a brim
• Speed: ~30–40 mm/s, cooling on
• Filament: white or natural PLA
• Model: max ~3 mm, min ~0.8 mm, contrast up slightly

FAQ

Why does my lithophane look washed out?

Usually not enough thickness range or too weak a backlight. Increase max thickness and contrast in the model, and use a brighter, more even light behind it.

Can I print a lithophane flat on the bed?

You can, but standing it upright almost always looks better — the horizontal layer lines read as smooth detail, and fine thickness changes come through more accurately.

Does infill really need to be 100%?

Yes. Sparse infill shows as patchy bright and dark spots when backlit and throws off the thickness-to-brightness mapping. Print it solid.