# How to 3D print a QR code

> Print the code in two colours (a light base with dark raised modules via a filament swap or multi-material setup), with modules at least 2 mm square and matt filament. Single-colour relief codes rely on shadows and scan unreliably. Extrude the SVG about 1 mm and scan a test piece first.

Source: https://useqr.app/docs/how-to/how-to-3d-print-a-qr-code · Last reviewed 2026-08-21 · UseQR is free forever, no signup.

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## Colour first, geometry second

A scanner needs luminance contrast, and a single-colour print has none, a
raised-module relief code in one filament depends entirely on shadows, which means it
scans under a desk lamp at the right angle and fails in diffuse light. It can work as an
art piece; it is not a reliable code.

The reliable approaches, ranked:

1. **Filament swap at a layer height** (any single-extruder printer). Print a light
   base, pause at the layer where the modules begin, swap to dark filament, finish.
   Every mainstream slicer supports a colour-change pause at a given layer. Result:
   dark modules on a light field: correct polarity, real contrast.
2. **Multi-material printing** (AMS/MMU/toolchanger). Same result without the manual
   swap, and the module layer can be flush rather than raised.
3. **Single-colour relief**, only with strong, raking light. Treat it as decorative.

Dark base with light modules is an inverted code: avoid it for the same reasons as in
any medium ([inverted codes](/docs/design/inverted-qr-codes)).

## The numbers

- **Module size ≥ 2 mm.** With a 0.4 mm nozzle that is five extrusion widths per
  module, enough for clean square corners. Below 2 mm, corners round and edges
  wander. A version 3 code (29 modules) at 2 mm modules is ~58 mm wide plus
  [quiet zone](/glossary/quiet-zone): size your plaque accordingly, and keep the
  payload short to keep the version down.
- **Module height 0.6–1.2 mm** raised (3–6 layers at 0.2 mm). Enough to be robust,
  shallow enough not to shadow itself.
- **Matt filament.** Matte PLA or similar; silk and glossy filaments produce specular
  highlights that read as false light modules. Avoid translucents entirely: light
  bleeds through thin dark layers, so give dark modules at least 3 layers.
- Print the code face **up on the bed's XY plane**: the top surface carries the detail.
  Printing face-down onto textured build plates also works and gives a flat flush
  finish; smooth PEI yields the cleanest face-down result.

## From code to geometry

Export the [SVG](/docs/how-to/how-to-make-a-qr-code-svg) and extrude it. In OpenSCAD it
is one line:

```scad
linear_extrude(height = 1.0) import("qr.svg");
```

Union that onto a base plate and you have the two-body model for a colour change.
Tinkercad and Fusion 360 import SVG the same way (the code is plain filled paths: see
[SVG path structure](/docs/spec/qr-code-svg-path-structure)). Alternatively, skip CAD:
several slicers can emboss an imported SVG directly onto a solid.

## Good payloads for a printed object

A 3D-printed code is permanent hardware, so encode things that stay true: a
[WiFi code](/wifi-qr-code) for a guest-network plaque, a short URL on a domain you
control for equipment or [3D-printed signage](/qr-codes-on/3d-prints), a plain-text
label for an asset tag. Skip anything you might need to change next quarter: reprinting
plastic is cheap, but re-installing fifty mounted plaques is not.

## Test before you print ten

Print one at draft settings, then scan it with [the scanner](/scan) in diffuse room
light, low light and sunlight, square-on and at 30°. If it only scans with a torch
raking across it, your contrast is shadow-based, go two-colour or increase the module
height difference. The general routine is in
[testing before printing](/docs/how-to/how-to-test-a-qr-code-before-printing).

## FAQ

### Can you 3D print a working QR code?
Yes, reliably, if it is two colours, dark modules on a light base via a filament swap or multi-material print. Single-colour relief codes depend on shadows and fail in ordinary lighting.

### What is the minimum module size for a 3D printed QR code?
About 2 mm square, five extrusion widths with a 0.4 mm nozzle. Combined with a short payload, that keeps a version 3 code around 6 cm wide, a sensible plaque size.

### How do I turn a QR code into an STL?
Download the SVG and extrude it in CAD (OpenSCAD's linear_extrude on the imported SVG is one line), then union it onto a base plate. Slicers with SVG embossing can skip CAD entirely.

### Which filament works best for QR codes?
Matt, opaque filaments in high-contrast pairs, matte black modules on white or natural base. Silk and glossy filaments create glare that reads as false modules, and translucents let light bleed through.

## Try it

- https://useqr.app/url
- https://useqr.app/wifi
- https://useqr.app/scan