RAW Paper Sizes

The ISO 217 standard defines the RA and SRA series of raw, untrimmed paper formats. RA stands for "raw format A" and SRA is "supplementary raw format A". These formats are slightly larger than the A series formats to allow for bleed during printing. After printing, the RA and SRA sheets are cut down to match the A series sizes. For example, RA0 is 1.05 square meters compared to 1 square meter for A0. Similarly, SRA0 is 1.15 square meters. The RA and SRA sizes have a 1:2 aspect ratio but the dimensions are rounded to the nearest centimeter, resulting in small deviations from the exact ratio. The RA sizes are also slightly larger than corresponding US inch-based sizes like ANSI A. Overall, the RA and SRA untrimmed formats facilitate printing bleed on oversized sheets that are later trimmed to common A series sizes.