Home › Guides

How to 3D print a two-color QR code

A QR code only scans if the phone can clearly tell the dark areas from the light ones. On a printed part, that means two filament colors: one for the base and one for the code. There are two ways to do it, and one of them works on any printer.

Before you start: download the right file

In the generator, choose the format and the two colors, then click “Download 3MF”. The file contains two parts already in place: the base and the raised code. When you open it in your slicer you should see them as two separate parts.

If your slicer asks whether to load the file as a single object with multiple parts, say yes. That keeps both parts aligned.

Option 1: printer with a multicolor system

If your printer changes filament on its own (AMS, MMU and similar), this is the easiest route:

Open the 3MF in your slicer.
Check that the base and the code have different filaments assigned. If not, select each part and assign it one.
Slice and check the layer preview: the code should only show the second color in the top layers.

Because the code is raised on a flat base, color changes only happen in the last few layers. That keeps print time and purge waste very low.

Option 2: single filament, changing color mid-print

You don't need a multicolor system. The trick is to print the whole base in one color, pause, and finish the raised code in the other.

Open the file and slice it normally.
In the layer preview, find the first layer that only contains the code and no base. The tool tells you the height (3 mm on most formats) in its printing notes.
Add a pause or filament change at that layer. Most slicers offer this by right-clicking the layer slider.
Start printing with the base color. When the printer stops, swap to the code color, purge until the new color comes out clean, and resume.

Settings that make a difference

Thin layers. At 0.2 mm or less, the edges of the code come out sharper.
0.4 mm nozzle. Enough if each module of the code is 1.5 mm or larger. The tool shows you that size.
Matte filament. Glossy or silk finishes reflect light and confuse the camera.
Light base, dark code. The combination every phone can read.
Good first-layer adhesion. A base that lifts at the corners distorts the code.

Common mistakes and how to avoid them

The code prints blurry. The modules are too small for your nozzle. Make the part bigger or shorten the link so the code has fewer modules.

Colors mix after the change. Not enough purge. Push more filament through before resuming, especially when going from a dark color to a light one.

The phone won't scan it. It's almost always low contrast or reflections. Try different lighting and distances; if it still fails, switch to a higher-contrast color pair.