The RA and SRA paper formats are defined by ISO 217 "Paper - Untrimmed Sizes" and cover untrimmed raw paper for commercial printing. The RA and SRA sizes are slightly larger than the corresponding A series sizes to allow for bleed on printed material that will be later trimmed to size, often for bound publication.
RA stands for "raw format A" and is conceptually defined as being 105% of the A series size, thus as A0 has an area of 1 square metre RA0 has an area of 1.05 square metres. SRA stands for "supplementary raw format A" and is conceptually defined as being 115% of the A series size, so a sheet of SRA0 paper has an area of 1.15 square metres. In reality the sizes for RA0, RA1, RA2, SRA0, SRA1 and SRA2 are rounded to the nearest centimetre and sizes for RA3, RA4, SRA3 and SRA4 are rounded to the nearest half centimetre.
Table of RA untrimmed paper sizes RA0 to RA4
The aspect ratio (the ratio of the width to the height) of the RA sheets is 1:root 2 (1:1.4142) as for the A series sheets.
Table of SRA untrimmed paper sizes SRA0 to SRA4
To obtain paper sizes in centimetres, convert mm values to cm by dividing by 10.
The aspect ratio (the ratio of the width to the height) of the SRA sheets is 1:root 2 (1:1.4142) as for the RA series sheets.
No comments:
Post a Comment