Are you looking for the official RA & SRA Paper Series? This post has all the information related to their respective size and dimensions.
Dimensions Of RA & SRA Series Untrimmed Paper Sizes
The standards for RA and SRA paper formats are defined under ISO 217 Paper Untrimmed Sizes. Moreover, they use untrimmed papers that are raw for the purpose of commercial printing. If we consider the size of RA and SRA, then they are slightly larger than the corresponding A series of paper sizes. This comparatively large size is to allow them to a bleed on the printed material so that they can, later on, be trimmed to the desired sizes as and when required.
RA is found to be 105% of the size of A series. Thus, if A0 is having an area of 1 square meter, then the RA0 will have an area of 1.05 square meters. SRA is considered to be 115% of the size of A series. Here, the full form of RA is Raw Format A and has a variety of sizes like RA0, RA1, RA2, RA3 and the full form of SRA is Supplementary Raw Format A which has size variants like SRA0, SRA1, SRA2, and SRA3.
Here, the variants RA0, RA1, RA2 and SRA0, SRA1, SRA2 are rounded off to the nearest of a centimeter and the variants RA3, RA4, SRA3, and SRA4 are rounded off to the nearest of half of a centimeter.
Tables Sizes of RA Paper Series
There is a table listed below which defines the untrimmed paper sizes that range from RA0 to RA4. The aspect ratio of the RA series lies in the range 1:1.414 whereas the aspect ratio of the SRA sheets of paper also lies in the range 1:1.414.
Table Sizes of SRA Paper Sizes
Here are the variants of sizes that are available in the Supplementary Raw Format A. Now, in order to obtain the values in cm you can divide it by 10.
Expansion of SRA Size Series
However, due to the increased demands and competition in the market, there are more SRA sizes that are becoming popular. The sizes like the SRA1+, SRA2+, and SRA3++ are most used. These sizes are equipped with an extra width that is more suitable for the newer printing machines.
This extra width enables the printer to grab the edge of the paper. So that you can turn it around for double-sided printing. This becomes possible because the printer is able to mark the paper when it picks it up. These sizes with increased widths are not defined in any International Standards. However, they have emerged in order to meet the increased demands of the current industries.