Braille fonts allow us to easily make braille labels on capsule paper. For legibility, fonts should be printed at optimum sizes. To find the optimum sizes for Japanese braille fonts, we conducted an experiment in which a Japanese braille font was printed at various sizes on capsule paper and read and rated by young braille users. The results show that braille printed at 17 and 18 point sizes were read faster and evaluated higher than those printed at smaller or bigger sizes.