jitsuyo

Jitsuyo (実用, practical use, utility) is the Japanese go term for the grade of shell stones considered everyday or utility quality. Shell stones as a class are preferred to glass or plastic.

Jitsuyo will have indistinct grain. Higher grades of stones include tsuki (curved or more widely spaced grain on stones) and yuki (grain runs straight across the stones with narrow spacing).

Jitsuyo grade size 38 stones

http://www.bresler.org/Go/Photos/Jitsuyo_box.jpg

Jitsuyo grades stones

http://www.bresler.org/Go/Photos/Jitsuyo_6stones.jpg