Ingen brought the Ming style of calligraphy to Japan and was exceptionally skilled with a brush.
Along with his disciples Mu'an (木庵性瑫 1611-84) and Sokuhi Nyoitsu (即非如一 1616-71), he was counted as one of the "Ōbaku no Sanpitsu" (黄檗三筆 "Three Brushes of Ōbaku").