RA1

The RA1 paper size is the second largest size in the ISO 217 series of raw, untrimmed paper formats. It has dimensions of 610 mm x 860 mm, giving it a surface area of approximately 0.525 square meters. The RA designation stands for 'raw format A' indicating it is based on the A series but oversized to allow for bleed during printing. RA1 is slightly larger than the more well known A1 size which is 594 mm x 841 mm. While not as large as RA0, RA1 is still useful for oversized commercial printing projects requiring bleed. Common uses include large technical drawings, architectural plans, educational posters, and folding maps. After printing, RA1 sheets are often trimmed down to A1 for binding or display. The 1:√2 aspect ratio of RA1 makes it easy to print 2 pages on a single sheet. Like other RA formats, RA1 originated from the ISO standards body in 1975 as part of the ISO 217 standard defining untrimmed paper sizes. Overall, with dimensions of 610 x 860 mm, RA1 provides a large raw paper format for printing projects needing bleed allowance.