Impressão de QR Code: Papel, tinta e resolução
Print specifications: DPI, ink types, paper stock, lamination, and quality control for reliable QR code reproduction.
QR Code Printing: Paper, Ink, and Resolution
Print quality directly affects QR code scannability. Understanding DPI, ink behaviour, and paper characteristics prevents costly reprint cycles.
Resolution (DPI)
Minimum DPI by QR code size and version:
| QR Size | Version 2 (25 mod) | Version 5 (37 mod) | Version 10 (57 mod) |
|---|---|---|---|
| 2 cm | 318 DPI | 470 DPI | 724 DPI |
| 3 cm | 212 DPI | 314 DPI | 483 DPI |
| 5 cm | 127 DPI | 188 DPI | 290 DPI |
| 10 cm | 64 DPI | 94 DPI | 145 DPI |
Rule: Each module must be at least 2 pixels wide at print resolution. Lower resolution causes module edges to blur together.
Ink Considerations
Laser printing: Sharp edges, high contrast, excellent for QR codes. Preferred for small codes on business cards and labels.
Inkjet printing: Adequate for larger codes (3 cm+). Watch for ink bleed on absorbent paper, which merges adjacent dark modules.
Offset printing: Professional quality. Specify minimum dot size to prevent fine modules from dropping out in the plate-making process.
Screen printing: Works for large-format codes. Mesh density must support the module size. Minimum 200-mesh for codes under 10 cm.
Paper and Substrate
| Material | QR Code Performance | Notes |
|---|---|---|
| Smooth coated paper | Excellent | Best for small, high-density codes |
| Uncoated bond | Good | Slight ink absorption; use larger modules |
| Newsprint | Fair | Significant absorption; increase size and EC level |
| Cardboard | Good | Smooth side preferred |
| Vinyl/plastic | Excellent | Weather-resistant; matte finish preferred |
| Metal | Good-Excellent | Laser etching or screen printing |
| Fabric | Fair | Large modules only; thermal transfer best |
Lamination
- Matte lamination: Ideal — reduces glare, preserves contrast
- Gloss lamination: Can cause scanning issues from reflective glare
- UV coating: Similar to gloss — use selectively (matte spot UV over the QR code)
Key Takeaways
- Each module needs at least 2 pixels at print resolution
- Laser printing is ideal for small QR codes; offset for production runs
- Smooth paper produces sharper modules than absorbent stock
- Matte lamination is preferred over gloss to avoid scanning glare
- Test on the actual production paper before the full print run