Glossary · Use

3D printing

Lithophane

A thin image that only becomes visible against the light: thin areas let a lot of light through and look bright, thick ones look dark.

Explained in more detail

For a lithophane, a photo is converted into a relief of varying thickness. Held in front of a light source, thin areas look bright and thick areas look dark, which produces a greyscale image. In 3D printing, online generators or functions in some slicers create the model directly from a photo, as a flat plate, curved, as a cylinder for lamps or as a sphere. Lithophanes are usually printed in white PLA with a small layer height and full infill, so that no infill patterns show through. Many guides recommend printing flat lithophanes upright, because the differences in thickness then come from movement in the plane instead of from the layer height.

Where does the term come from?

From Greek lithos, "stone", and phainein, "to make visible, to appear". The first patent was granted in Paris in 1827, and lithophanes were originally made of thin porcelain.

In practice

• Use white or natural-coloured filament; coloured filament distorts the greyscale.
• Match the minimum and maximum thickness in the generator to your filament: areas that are too thin let too much light through, and areas that are too thick look black.
• Photos with strong contrast and clear subjects work better than flat shots.
• Use LEDs for lighting that give off hardly any heat. PLA softens from around 55 °C.

Not to be confused

A lithophane is not multi-colour printing: it shows greyscale purely through material thickness. Coloured lithophanes only arise when several filaments are combined in multi-colour printing.

Frequently asked questions

Which filament is suitable for lithophanes?

Usually white PLA. It lets light through well and prints finely. Transparent filament is less suitable because it creates hardly any contrast between thin and thick areas.

Why does my lithophane look like nothing without light?

That is normal. The image is in the thickness and only becomes visible when light shines through from behind. In reflected light you only see an uneven relief.