How to use every tool on the site and how to get a great print out of it — start to finish
A lithophane is a 3D print that looks like a plain, pale panel in normal light — but reveals a detailed photo when you shine light through the back. It works because of thickness:
This tool converts every pixel's brightness into a height, so dark parts of your photo print thick and bright parts print thin, then exports a printable STL for your slicer (Cura, PrusaSlicer, Bambu/Orca Studio, etc.).
The photo matters more than any setting. Best results come from images that are:
Tip: always click Preview after changing settings so the output reflects your latest choices.
Beyond a plain rectangle you can crop the lithophane to: Circle, Oval, Heart, Diamond, Hexagon, Octagon, Star, Rounded Rectangle, Arch, and Egg.
The exported STL matches the on-screen shape exactly, and the edges are watertight (closed) so they slice cleanly.
Tick Add hanging hole to punch a hole near the top — perfect for ornaments and keychains. Set the diameter and the distance from the top. Works with any shape except a plain Rectangle.
Tick Add raised frame to add a raised rim around the shape edge (shown as an orange dashed line on the preview).
On the Flat generator, tick 🎨 Two-colour print (filament change) to print the base in one colour and the photo in another on a single-extruder printer. It shows the exact Z height to add a colour change in your slicer (PrusaSlicer/Orca: right-click the layer; Cura: Pause at height / Filament change) — load colour 1 first, swap to colour 2 at the prompt, and print standing up. For truly separate colour bodies on an AMS/MMU, use Send to 3D Designer, add a coloured backplate and export 3MF.
On the photo generators (flat, cylinder, cone, cube, globe, lantern, multi) you'll see a Send to 3D Designer button next to Generate. It hands your finished lithophane straight into the in-browser 3D Designer so you can:
Click Save Settings (.txt) to download a text file listing every setting used (size, thickness, shape, hole, frame, image adjustments, etc.). Keep it next to your STL so you can reproduce or tweak a print later.
Everything here is free to use — every lithophane shape and the full 3D Designer. A free account is needed to download STL files.
Image to STL traces the outline of a picture and pulls it up into a solid shape. Drop in a PNG, JPG, WebP or SVG and pick one of three styles:
Contrast is everything. A black-on-white logo traces perfectly; a photograph of a person does not, because there is no single brightness that separates them from the background. Photographs belong in the lithophane generators, which use every grey level instead of one cut. Transparent PNGs are the easiest input of all — the cut-out edge is already exact, so the threshold barely matters.
Text to STL turns typed text into a printable model: name plates, door signs, keyring tags, fridge magnets and spray stencils. It uses any font installed on your computer — pick from the list or type a font name — with bold, italic, letter spacing, multiple lines and alignment.
Sizes are measured on the letters themselves, not on the font's invisible box, so 20 mm tall means 20 mm tall whichever font you choose. With more than one line, that height covers the whole block.
Add a hanging hole for a keyring or hook and the plate grows to make room for it, so the border you set around the lettering stays exactly as you set it.
Engrave & Emboss puts a name, logo or picture onto a model you already have — cut into the surface, or raised out of it. Load an STL, choose text or a picture, pick which face it goes on, then drag it into place on an outline of your own model.
Print on Fabric makes lace cards — wedding invitations, place cards, RSVPs — by printing a pattern onto tulle, organza or chiffon. It gives the laser-cut look without a laser cutter, and without the connecting bridges a cut-out design normally needs.
The print runs in two halves. A few tenths of a millimetre go down first, the printer pauses and parks, you lay the fabric over the top and pull it taut, and then the rest prints over it. Plastic squeezes through the weave and welds to the plastic below, trapping the fabric in a sandwich.
Five lace patterns are built in and all of them are adjustable, or bring your own artwork and add names and a date. Expect to lose a couple while you find the right fabric tension — print a small place card first rather than a full invitation.
The 3D Print Tools (under Tools in the menu) take any STL — not just lithophanes — and remove material from the inside, so it prints faster and uses far less filament. A solid model is usually mostly wasted plastic.
Two things worth knowing before you start:
Because it runs on your own machine, a very large or very detailed model needs a reasonably modern computer. If a setting would produce something too big to build, the tool says so and suggests what to change rather than freezing.
| Mode | What it does | Good for |
|---|---|---|
| Hollow shell | Keeps only the outer skin at a wall thickness you choose. | The biggest saving. Vases, statues, anything you never see inside. |
| Perforated | Hollow, then punches a pattern of round holes through the skin. | Lampshades and anything that should let light or air through. |
| Hex frame | Turns the skin into a honeycomb of hexagonal cells that follows the shape. | A strong, light, decorative cage. Looks hexagonal from every angle, not just one. |
| Lattice infill | Fills the inside with a gyroid, Schwarz-P or diamond lattice. | Parts that must stay stiff. Self-supporting, so it prints without supports. |
| Wireframe | Reduces the model to struts along its edges, with balls at the joints. | Sculptural, skeletal versions of a shape. The largest saving of all. |
Settings that matter most: wall thickness (1.2–2 mm suits most FDM prints — thinner walls warp), and a drain hole if you print in resin or SLS, so trapped material can escape. Higher resolution captures finer detail but uses more memory and time.
STL files carry no agreed "up" direction, so a model exported from some programs arrives lying on its side. Under the Original model preview you'll find Rotate model with X, Y and Z boxes, quick +90° buttons and a Reset.
The rotation is applied to the real file, not just the picture — so what you see in the preview is what gets converted or sliced. Orientation matters for printing too: see Orientation below.
The Print Doctor answers the question worth asking before you start a six-hour print: will this actually work? Load an STL, tell it your nozzle's limits, and it checks four things.
| Check | What it finds |
|---|---|
| Watertight | Holes in the surface, edges shared by more than two faces, faces pointing the wrong way, stray pieces and zero-area triangles. |
| Wall thickness | A colour map of everything too thin for your nozzle to print, measured with the largest sphere that fits inside the wall — so it is honest about thin diagonal ribs. |
| Overhangs | Every surface that will need support, shaded by how far it leans. Anything already resting on the plate is sensibly left out. |
| Orientation | Tries a few hundred ways up and shows the best three, with how much support each one saves. One click fills in the rotation boxes. |
There are two repairs. Quick fix removes junk triangles and makes every face agree which way is out — it moves no vertex, so sharp edges stay sharp. Rebuild re-creates the surface from scratch, which resolves tangled and overlapping geometry, at the cost of re-meshing everything.
The 3D Print Simulator slices an STL the way your printer would and shows you the result before you commit any filament. Walls are drawn in orange, infill in blue, and you can drag the slider or press play to watch it build up layer by layer.
Set your own layer height (0.2 mm is the usual default), nozzle diameter (0.4 mm on most printers), number of perimeters, infill percentage and bed size. It reports the estimated print time, filament length and weight, and warns you if the model does not fit your bed. You can download the G-code at the end.
Most printing problems are the printer, not the model. Calibration & Test Prints generates seventeen tuning models sized to your printer, with the values printed on them so you can read the result afterwards — no more counting bands to work out which floor was 210 °C. Each one also explains what a good result looks like and which setting to change.
New printer? Work down this list in order. Each test depends on the ones before it — a retraction test on a printer with a bad first layer is wasted filament.
The rest are for chasing a specific problem: overhang angles and bridging to find your printer's limits, clearance and hole size gauges for parts that have to fit together, thin walls and small features for how fine you can go, support gap for supports that snap off cleanly, plus a warping plate, a cooling spire, a text legibility ladder and the XYZ cube. Change one thing at a time, and print each test with the settings you actually use.
Open the STL in your slicer. These settings make or break a lithophane:
| Setting | Recommended | Why |
|---|---|---|
| Layer height | 0.10 mm (0.08 mm best) | Thin layers = smooth tones and fine detail. |
| Line width | 0.4 mm | Matches the nozzle; crisp walls. |
| Infill | 100% | Any gaps let light leak unevenly. Must be solid. |
| Print speed | Slow — 30–40 mm/s | Cleaner walls, better detail. |
| Supports | Usually none | Upright panels and curved walls are self-supporting. |
| Cooling / fan | 100% | Good cooling sharpens fine relief. |
Many slicers include a "Lithophane" profile, but the table above is all you really need.
| Problem | Likely cause & fix |
|---|---|
| Washed out / low contrast | Increase Contrast and Max Thickness; pick a punchier photo; use whiter filament. |
| Too dark when lit | Lower Max Thickness or raise Brightness/Gamma; use a stronger backlight. |
| Light leaks / blotchy glow | Set infill to 100% — it isn't fully solid. |
| Visible layer banding | Smaller layer height (0.08–0.10 mm) and slower speed. |
| Image mirrored / back-to-front | Use Flip Horizontally, or flip in your slicer. |
| Generation slow / file huge | Lower Mesh Subdivision or use the Balanced/Fast preset. |
| Nothing happens on Generate | Click Preview first so a brightness map exists. |
| Won't stick / wobbles | Add a brim, clean the bed, check first-layer levelling — then print the first layer patches. |
| Slicer refuses the file, or fills the wrong bits | The mesh is probably not watertight. Run it through the Print Doctor, which will name the fault and often fix it. |
| Thin details or lettering missing from the print | They are narrower than your nozzle can draw, so the slicer drops them. The Print Doctor maps them in colour; scale the model up or thicken those parts. |
| Rough, droopy undersides | Overhangs printing without support. Check the angles in the Print Doctor and let it suggest a better orientation. |
| Stringy, blobby or brittle prints in general | Not the model — the printer needs tuning. Work down the calibration prints in order. |