The area of the afghan is exactly one square metre (That does not mean it is one metre square). Each rectangle shows a different size of paper. One of the photographs shows sheets of A3 and A4 placed on the afghan.
It consists of four rectangles stitched together. I decided one large rectangle would have resulted in large, boring, blocks of colour. I like the illusions created by reversing the colours in two of the rectangles.
The technique is similar to log cabin so it is very easy to make.
If you are inot in Europe you may not be aware of the magical properties of metric sized paper. Regardless of what size paper you begin with, folding a sheet of paper gives you another rectangle exactly the same shape as the original but with half the area. The standard size of paper for everyday use is called A4.
Multiply the length of one side by the square root of 2 (approximately 1.4) and you get the length of the other side.