What matters most
- 0.20 mm is a practical starting layer height for many 0.40 mm nozzle QR prints.
- Feature depth should usually span multiple layers rather than one thin layer.
- Finer layers can improve Z detail but do not fix modules that are too narrow in XY.
- Coarser layers require deeper features and often pair with larger nozzle/module targets.
Layer height solves a different problem than module width
The QR matrix is primarily an XY pattern. Nozzle diameter and extrusion width strongly influence how well the square modules reproduce in that plane. Layer height controls Z resolution: how many layers build the base and how many layers create the raised or recessed feature.
A 0.12 mm layer cannot rescue a 0.30 mm-wide module that the nozzle cannot draw cleanly. Likewise, a generously wide module can still have a weak relief if the feature is only one layer high.
Practical starting profiles
These values follow ModuQR’s current profile logic: strong feature depth is at least three layer heights or 1.5 nozzle diameters, whichever is larger. The base target is at least six layer heights or three nozzle diameters. They are conservative design checks, not universal printer specifications.
| Profile | Nozzle | Layer height | Strong feature depth | Strong base target |
|---|---|---|---|---|
| Fine | 0.25 mm | 0.12 mm | ≥ 0.40 mm | ≥ 0.80 mm |
| Standard | 0.40 mm | 0.20 mm | ≥ 0.60 mm | ≥ 1.20 mm |
| Coarse | 0.60 mm | 0.28 mm | ≥ 0.90 mm | ≥ 1.80 mm |
Why 0.20 mm is a strong general starting point
With a common 0.40 mm nozzle, 0.20 mm layers balance print time, surface quality and predictable Z features. A 0.60 mm QR relief becomes roughly three layers deep, giving the feature more presence than a single-layer texture.
For a simple sign, that is often easier to inspect and reproduce than an ultra-fine layer stack. If your printer is well tuned and the object needs finer surface detail, 0.12–0.16 mm can work, but the QR still needs enough XY module width.
Recessed QR codes need a remaining floor
Engraving depth cannot be considered alone. After subtracting the recess from the base thickness, enough material must remain under the cavity. ModuQR checks this remaining floor and limits recessed geometry so the model does not become paper-thin below the QR.
When using coarse layers, avoid choosing a recess depth that lands awkwardly between too few layers. A depth built from several full layers is easier to reason about in the slicer preview.
Layer-height checklist
- Choose nozzle size first.
- Pick a layer height appropriate for that nozzle and your normal printer profile.
- Set QR feature depth so it spans several layers.
- For recessed mode, confirm the remaining floor under the engraving.
- Inspect the top or cavity layers in the slicer preview.
- Print a small test if you use ironing, adaptive layers or unusual top-surface settings.
A reproducible check before you print
Keep the QR payload fixed and change one variable at a time. Watch physical module size and ScanSafe warnings, export the same model to your slicer and inspect the layer preview. The final check is still to scan the finished physical object with a real camera.
Read the editorial and technical methodologyPrimary sources and technical documentation
These references support QR requirements, file formats or general printing constraints. ModuQR-specific FDM targets are labeled as heuristics rather than requirements from these sources.
- ISO/IEC 18004:2024 — QR Code symbology specification — ISO
- Creating profiles for different nozzles — Prusa Knowledge Base
- Layers and perimeters — Prusa Knowledge Base
Check feature depth against your layer height
Set the print profile in ModuQR and review relief, engraving, base and remaining-floor guidance before export.