How to 3D print a QR code

2026-09-01 · 7 min read

You already have the file. What follows decides whether the piece scans on the first try or ends up in a drawer.

Opening the file

If you downloaded the 3MF, open it directly: you'll see two or three separate bodies with their colors. If you downloaded the STL ZIP, import all the files at once and say yes when the slicer asks if you want to treat them as a single multi-part object (or place them all at position 0,0).

Settings that matter

Orientation

The code's face always up. Plaques and keychains print lying flat; table stands rest on their base, with the angled face looking toward the ceiling. Never print the code against the bed: the sheet's texture transfers to the relief and ruins the detail.

Two colors without a multi-material printer

1. Slice the whole piece as if it were a single color.
2. Find your slicer's filament change or pause at height feature.
3. Insert it at the exact height of the base's thickness (say, 3.0 mm).
4. When the printer reaches that point it will stop: pull the filament, load the other color, purge well, and resume.

The result is indistinguishable from a multi-material print and needs no extra hardware. The only care needed is purging enough that no traces of the previous color show up in the relief's first layers.

Materials

• Matte PLA: the best choice indoors. Easy to print and no shine to ruin the scan.
• PETG: for outdoors, keychains and hot spots. More durable, a bit trickier.
• ASA: outdoors with constant direct sun.
• Avoid: glittery, silk or metallic-effect filaments on the code piece: they reflect and confuse the camera.

If it doesn't scan

1. Check the real contrast under the light where it'll be used.
2. Measure a module with calipers: if it's under 1.5 mm, make the piece bigger.
3. Check whether the modules touch each other (nozzle too wide, or over-extrusion).
4. Try another phone: some older cameras are much less forgiving.
5. Make sure the margin around the code is clear.