Many canvases and wood panels, etc. used for art generally have specified dimensions annotated by a numeric designator. Those used in Japan today were originally based on French specifications expressed using the Japanese measurement units shaku and sun, and were converted to metric when the Japanese measuring system was abolished (1 shaku = approx. 30.3 centimeters). Because this conversion consequently resulted in discrepancies, there are some minor size differences between Japanese specifications and those used in France. There are 25 designated numeric designators used in Japan today, including special specifications, ranging from 0 to 500 and each code has different long and short side ratios. They include F (Figure), P (Paysage) (Landscape), M (Marin) (Marinescape) and S (Square). The long and short side ratios of each type equal a golden rectangle: F-type (√5-1):1, P-type √2:1, M-type (√5+1):2. In fact, when the long sides of two F-type canvases (same size) are joined together, they also form a golden rectangle.
- Standard canvas sizes in Japan (units: mm)The height and width of each S (square) size are equivalent to the length of the long side for the corresponding number.