Elongated A Paper Sizes

ISO 5457, last updated in 1999, introduces elongated paper sizes that are formed by combining the short side dimension of one A-series size (e.g. A2) with the long side dimension of a larger A-series size (e.g. A0). This results in new sizes like A2.0 which has dimensions of 420 x 1189 mm. These elongated sizes have been adopted by ANSI/ASME Y14.1 alongside the standard A0-A4 sizes and inch-based sizes for use in the United States. The elongated sizes provide more flexibility in paper dimensions while maintaining the width-to-length ratio of standard A-series sizes.