How to measure

There’s nothing to measure on your end — pick the panel size and thickness you want. A good starting point is 100 x 140 mm at 0.8–3.2 mm: big enough to show real detail, thin enough to print quickly and transmit light well.

Print settings

• Orientation: flat prints face up, directly on the bed. Curved and cylinder shapes print exactly as generated, axis vertical — no reorienting needed.
• Infill: 100% — every shape here is thin enough that infill percentage barely changes print time, and full infill avoids visible internal line patterns showing through the thinnest areas once backlit.
• Layer height: fine (0.1–0.12 mm) smooths the brightness gradient between layers; anything coarser bands it.
• Filament: light, natural, or clear/white filament transmits the most light. Dark filament reads flat even backlit, no matter how good the model is.
• Supports: flat and cylinder never need them. A wide curved arc (past roughly 180°) can curve back past a printable overhang angle on its underside — check the preview from below before printing without supports.

FAQ

Why is my print too dark, or too washed out, overall? Try the Brightness and Contrast sliders first before changing thickness — a photo shot in low light usually needs both a brightness boost and a contrast bump to read well once printed.

What’s Positive vs Negative? Positive (the default) makes dark areas of your photo print thick, so they block more light when backlit — this matches how the photo actually looks. Negative inverts it, which can look more like a photographic negative held up to light.

Can I upload a HEIC photo from my iPhone? Not yet — export or share it as a JPEG or PNG first. HEIC support across browsers is inconsistent enough that a clear “not supported” message beats an unreliable partial decode.

Does my photo get uploaded anywhere? No. It’s read locally in your browser, processed locally, and never sent to a server — not even as part of a shared settings link, which is why re-opening a link to one of your own lithophanes on another device shows a blank placeholder until you re-upload the same photo there.

Can I curve the panel, or wrap it into a cylinder? Yes — the Shape control has Flat, Curved (pick any arc angle) and Cylinder (a full wrap, open through the middle for a light source). A stand or frame isn’t built yet.

Why does Cylinder have a hole all the way through? By design — it’s meant to slip over or sit around a light source, the same way a real lamp shade works.