The Golden Rule: The 10:1 Distance-to-Size Ratio
The number one reason QR codes fail in real-world print campaigns is incorrect physical sizing. A QR code printed too small on a highway hoarding or event banner cannot be resolved by standard smartphone camera sensors.
The industry standard formula for QR code sizing is: $$\text{QR Code Width} = \frac{\text{Scanning Distance}}{10}$$ For example, if a user will scan your QR code from **1 meter (100 cm)** away, the QR code matrix should be at least **10 cm × 10 cm** wide.
Standard Print Size Recommendations
The Quiet Zone (Margin) Requirement
Every QR code requires an unobstructed border known as the **Quiet Zone**. This margin should be equal to at least **4 modules (blocks)** of space around all four sides. Cropping the border too close or placing illustrations right up against the QR corners prevents camera algorithms from detecting the finder patterns.
Vector SVG vs Raster PNG: Always Print from Vectors
Never scale up a 300px PNG image in Photoshop for print production — doing so introduces anti-aliasing blur along the module edges, causing camera read failures. **Always export in Vector SVG format from QRnaly.** SVG files can be scaled to billboard proportions in Adobe Illustrator or CorelDRAW with 100% mathematical edge sharpness.
Color Contrast Standards
Ensure a high contrast ratio between foreground modules and background color (at least 4.5:1, ideally pure dark on pure white). Avoid light gray on white or dark blue on black backgrounds.