Mineo Yamamoto covers a flounder with paper and dabs it with an ink-covered tampo, a small bulb of cotton wrapped in fine silk and named for its resemblance to a dandelion. Slowly, the fish emerges in fine detail.

Yamamoto, 82, who runs the International Fish Print Studio in Higashimatsuyama, Saitama Prefecture, 90 minutes from central Tokyo, is demonstrating to students the art of gyotaku — literally, “fish printing.” The monochrome prints, created by applying sumi ink on the fish and then pressing it onto washi paper, originated in the mid-19th century as a way for Japanese fishermen to create records of their catches with added details such as the date, location, fisher’s name and, sometimes, a witness’ signature.

Yamamoto began teaching himself gyotaku to document the fish he caught. It was not until a year later, at a boating fair, that he saw the medium’s artistic potential while watching a full-color print of a red sea bream being made.