For sharp printing at standard trading card size (2.5 × 3.5 inches), you need:
- Minimum: 1500 × 2100 pixels (300 DPI at print size)
- Ideal: 2000 × 2800 pixels or higher (allows cropping flexibility)
- Maximum file size: 20MB (JPG, PNG, or HEIC)
Most modern smartphones exceed these requirements. Check your phone's camera settings — use the highest resolution available.