An exhibition showing 103 publicly unseen sketches by Japanese ukiyo-e artist Katsushika Hokusai will open at London's British Museum on Thursday.

The postcard-sized sketches were created by Hokusai (1760-1849) in the 1820s to the 1840s and were intended to become woodblock prints for a visual encyclopedia titled "The Great Picture Book of Everything," which covered topics from the natural world to Buddhist lore and life in ancient India and China.

According to the museum, the volume was never published and the so-called "block-ready" drawings, or hanashita-e, were preserved in their original form.