“What is the sound of one hand clapping?” This is one of the puzzling questions Zen Buddhist masters would have asked their pupils to help them achieve enlightenment (satori 悟). These “koan” (公案), paradoxical and spiritual tests that elude any solutions by logical thinking, were often the anecdotal dialogues of great monks and were an important aspect of Zen training. Another common exercise used to achieve this enlightenment was artistic practice. Traditional symbolism, or the simple representation of nature, could not achieve this. On the contrary, Zen painting (zenga 禅画) seeks to represent the instant spirit of an action through suggestive abbreviations, unconventional allegories and calligraphy. Brushstrokes can affect the spiritual capture of satori at the exact moment of its action. In other words, the ink brush itself expresses the concept of the mind. It is pointless to describe the experience of Zen as expressed in art. According to Zen perception, art stands by itself, without any meaning. Even though there is a complex background of symbols and allegories, a convincing interpretation is not always possible. Understanding Zen works hence means immersing oneself in the painting, and reaching enlightenment through an unconscious emptying of oneself.