A Guide to 'A' Paper Sizes
The A sizes in scale to one another.
When it comes to choosing paper to create art works on, paper dimensions will inevitably vary throughout sheets and pads. However most people will have come across the A Sizes of paper at some point; whether it be in art work or the form of simple documents. The advantages of basing paper upon this ratio were first introduced in 1786 by German scientist and philosopher Georg Christoph Lichtenberg and in 1975 they became an official metric standard. As seen in the image above, A Sizes begin with A0 and typically range to A7. Each step up in A Size represents half of the previous size sheet. A1 is half the size of A0, A2 is half the size of A1 and so on. By sizing paper through this method, sheets and pads can be mass produced into smaller and smaller products without losing the aspect ratio or weight calculation of paper. Due to A Sizes still being relatively modern in artists paper, they are most commonly used as a size guide for copy paper, convenience pads and sketchbooks.
Traditionally, however, paper dimensions were measured in inches using a system called Imperial. It is still popularly used in the production of Watercolour papers and pads. Since the best of watercolour papers are hand made, Imperial sizes are only approximate and usually start with the size Imperial, a 22 x 30 inch sheet, the size of the paper mould itself. Other traditional sizes are Demy, 15" x 20"; Medium, 17" x 22"; Royal, 19 x 24" and Super-Royal, 19" x 27". Most formats of Watercolour Paper will still only be available in Imperial sizes.