When supplying a QR code for publication in a newspaper, the characteristics of offset printing on newsprint must be taken into account. Due to dot gain, elements may spread slightly, which can negatively affect scannability. To ensure optimal readability, we recommend the following guidelines:
- Size: minimum 25 × 25 mm. Smaller QR codes are not recommended due to the risk of pixels filling in.
- Colour use: use 100% K only. Avoid building the QR code from CMYK colours or using light tints to prevent registration errors and loss of contrast.
- Background: always place the QR code on a plain, light background. Avoid placing it over photos, illustrations, busy visual elements, transparency effects, or gradients.
- File format: preferably supply the QR code as a vector file, such as EPS or vector PDF, for optimal sharpness and reproducibility. Alternatively, a high-resolution bitmap file can be used, with a minimum of 300 to 600 dpi at final size.
- Quiet zone: keep at least 2 to 3 mm of white space around the QR code, free from text, images, and other graphic elements.
- Testing: test the QR code in advance by making a proof print at actual size and scanning it under different conditions. This minimises the risk of scanning issues in the final newspaper.
These guidelines help ensure optimal scannability of QR codes in newspaper printing.