Technical Requirements
For sharp, professional output, your A3 images need sufficient resolution. The minimum resolution suggested for printing an A3 poster is 2700 x 3600 pixels, or 150 DPI at 100% size. At the industry-standard 300 DPI, the recommended pixel dimensions for A3 are approximately 3508 x 4961 pixels for the printable area. This ensures your poster avoids pixelation and maintains crisp detail. When you add a standard 3mm bleed on all sides (essential for commercial printing), the dimensions expand to 3579 x 5031 pixels.
Acceptable DPI ranges depend on viewing distance and application:
300 DPI (approximately 3508 x 4961 pixels): Required for close-up viewing, photographic quality, and commercial print
150 DPI (2700 x 3600 pixels): Acceptable for posters viewed from 1-2 meters or internal drafts
72-100 DPI: Only suitable for digital display, never for print
