Image to STL (Lithophane Maker)

About the Image to STL (Lithophane Maker)

Make a 3D-printable STL from a picture. A lithophane turns a photo into a thin panel whose thickness follows the brightness — dark parts thick, light parts thin — so the picture appears when light shines through it. Make it flat, curved (an arc you can stand up) or a cylinder for a lamp shade, with thickness, size, border and contrast controls. For logos and drawings, make a raised relief (a plate with the shape standing up — signs, name tags or, mirrored, a stamp) or a cookie cutter that follows the outline of the shape, with a wall and a flange to press on.

Turn the model around in the 3D preview, check the simulated back-lighting of a lithophane, and download a binary STL in millimetres, ready for your slicer. Everything is computed in your browser; the picture is not uploaded.

Common uses

• Lithophane gifts, night lights and lamp shades from family photos
• Name plates, door signs and stamps from logos (mirror the relief for a stamp)
• Cookie cutters in the shape of a drawing, a logo or a child’s sketch
• Turning a height map (a grey image) into a printable surface

How the models are made

• Lithophane: each surface point takes its thickness from the brightness (BT.709 luma) of the picture: the darkest parts get the thickest setting, the brightest the thinnest. The contrast curve bends this line; negative swaps it. The picture reads the right way round from the patterned side of a flat panel and from the outside of a curved panel or cylinder.
• Raised relief: points above the threshold (dark, light or opaque parts — your choice) are raised by the relief height on top of the base, following the picture’s own smooth (anti-aliased) edges.
• Cookie cutter: the picture’s largest shape is taken, holes filled, and the picture is cropped to it, so the size you set is the longest side of the shape itself, however much empty margin the picture has. Its outline comes from an exact distance transform (Felzenszwalb & Huttenlocher), and the wall (centred on the outline) and the flange (outside it) are cut along those distances, so the walls are vertical and the outline smooth. The STL is mirrored left to right: the cutter is printed flange-down but pressed into the dough flange-up, which turns it over, so the cookie comes out the right way round — this matters for letters and other one-sided shapes.

Every model is a closed, consistently oriented mesh — each edge is shared by exactly two triangles — which is what slicers need.

Tips for lithophanes

Light passes through thin plastic more easily than thick, so the picture shows best in a light, translucent filament such as white PLA. Solid infill keeps the thickness alone in control of the light — a pattern inside the panel would show through. Strong contrast and a clear subject work best; very dark photos produce a mostly thick, dim panel, so brighten them first or use a contrast curve below 1. The simulated back-lighting is only a guide: real results depend on the filament and the light.

Limitations

• Only brightness is used: colours are not printed, and a relief or cutter uses one threshold for the whole picture.
• The cookie cutter follows the outside outline of the largest shape; inner details and separate small shapes are left out.
• Very fine detail is limited by the point spacing (the smallest is 0.1 mm) and by your printer’s nozzle.
• Large or fine models are capped at 1.2 million surface points; the tool raises the point spacing when needed and says so.
• Whether a printed cookie cutter is safe for food depends on the filament, the nozzle and the cleaning — check your filament maker’s food-contact information.

Privacy

Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.