A1 Poster Size
A1 poster size measures 594 × 841mm or 23.39 × 33.11 inch. In PostScript, its dimensions are rounded off to 1684 × 2384 points.
A1 size is typically used for posters, drawings and outdoor advertising.
Part of the ISO 216 standard
A1 is part of a set or range of page sizes, called the ISO A or ISO 216 standard. This international standard is based on the German DIN 476 standard from 1922. A1 is actually often referred to as DIN A1. The Japanese have adopted the same range of paper sizes in their JIS P 0138-61 standard.
By folding an A1 in two along its shortest side, you create an A2 poster. Two A1 pages next to each other in a spread equals the A0 paper size. This is a great way to understand the size.
What resolution required to print a picture on a A1 poster?
For A1 poster size, 150dpi is a good resolution. A1 is 33.1 in × 23.4 in you need (x150) => 4965×3510 pixel. That is 17.4MP, so if you use the full image (no crop) you’ll be fine.
If you are struggling with designing your posters or need help with what software is best, check out our blog from last year “Top 3 best software”