Definitions for "Oban"
"Large block," a vertical or horizontal print approximately 38 x 25.5cm (15 x 10 inches), the most common size of woodblock prints from the 1790s through the 19th century.
The most common print size; about 38cm x 25cm (15" x 10"). Oban tateye - An oban sized print in portrait ( tateye) orientation. Oban yokoye - An oban sized print in landscape ( yokoban) orientation.
Print size. Approximately 37 x 26 cm. The predominant print size throughout the history of Japanese woodblock prints.
Keywords:  koku, worth, coin, gold
A gold coin worth 10 koku.
about 15" x 10" or 38 x 25cm