A part of the documentation of the hand scrolls involved not only recording the position of all of the twenty-one paintings and the twenty-six calligraphy's but also their dimensions. For this we use a traditional Japanese bamboo ruler (monosashi) marked in shaku (1 shaku = 30.3 cm).
Originally Chinese and dating back to the Zhou Dynasty in the 13th century BC, the shaku was once the distance from the thumb to the middle finger (about 18.0 cm). However, like the taxes it was once linked to, it has increased over the centuries. In Japan there are several shaku measures still in use today, with the clothing industry and carpenters using completely different shaku measures.
The dimensions of scrolls and their various mountings are always in these units of measure, as are most of our tools, materials and equipment. So... mo, rin, bu, sun and shaku are the standard measures in scroll mounting studios. For the record 'The Tale of the Bamboo Cutter' scrolls are 9 sun high and an impressive 95 shaku, 3 sun, 6 bu long - give or take a mo (the width of a human hair!)
A Japanese shaku ruler |