Slicer settings for a crisp raised QR code
Default settings usually work, but a few tweaks make a real difference on small parts like keychains and business cards.
General settings
| Setting | Value | Why |
|---|---|---|
| Layer height | 0.16–0.2 mm | Finer = sharper module corners |
| First layer | 0.2 mm | Good adhesion without squish |
| Infill | 15–20% (100% for cards) | Enough stiffness |
| Walls | 2–3 | Clean edges |
| Outer wall speed | ≤ 100 mm/s | Less ringing on the relief |
| Supports | Off | No object needs them |
| Ironing | Top layer of the base only | Smooth background = more contrast |
Bambu Studio and OrcaSlicer
- Open the 3MF; accept loading it as one object with multiple parts.
- In the object list you'll see “Base” and “QR code and text”: assign a filament to each.
- Use “0.16mm Optimal” for keychains and cards, “0.20mm Standard” for the rest.
- No AMS: in the preview, right-click the first relief layer → “Add filament change”.
PrusaSlicer
- Import the 3MF: you'll get one object with two parts.
- Pick the extruder for each part (or keep one and use a color change).
- Profile “0.15mm QUALITY” or “0.20mm SPEED”.
- Color change: on the vertical layer slider click “+” at the first relief layer (inserts M600).
UltiMaker Cura
- Open the 3MF or import both STLs together and group them (Ctrl+G).
- Single extruder: Extensions → Post Processing → Modify G-Code → “Pause at height” at the height where the relief starts (base thickness).
- 0.16 mm layers and combing off over the relief.
Where the relief starts
| Object | Pause height |
|---|---|
| Keychain / coaster | 3 mm |
| Plaque | 3.2 mm |
| Magnet | 4 mm |
| Card | 1.8 mm |
| Table stand | Tilted: use multicolor or paint the relief |
💡 On the table stand the code sits on a tilted face, so there's no single layer where the relief starts. Use a multicolor system (AMS/MMU) or print in one color and paint the relief with a roller.
Common problems and fixes
| Symptom | Likely cause | Fix |
|---|---|---|
| Modules merging | Over-extrusion or modules < 1.5 mm | Calibrate flow, enlarge the code |
| Strings between modules | Low retraction or wet filament | Increase retraction, dry the filament |
| Relief lifting off the base | Long pause or cold base | Resume quickly; add 5 °C |
| Light color bleeding into the relief | Insufficient purge | Increase purge or tower volume |
| Infill pattern showing on the base | Too few top layers | Use 4–5 top layers or ironing |
Speed or quality
Fast printers (Bambu, Prusa Core One, Creality K1) print a QR code fine at standard speed, but on small parts fast outer walls cause tiny ripples that soften module corners. If the code will be on display, halve the outer wall speed: total time barely changes because the relief is so thin.
Printing many at once
For batches (wedding keychains, magnets for a restaurant) place all copies on the plate and add a single pause: they all share the same relief height. Keep at least 5 mm between parts so the nozzle doesn't knock any over.