Franks was also an authority on classical art, especially Roman remains in Britain. He set up an exhibition of his Asian ceramics, mainly porcelain, at the Bethnal Green Museum in 1876. He collected "netsuke" and "tsuba" from Japan, finger rings and drinking vessels. He was interested too in bookplates and playing-cards, of both of which he formed important collections; the friendship of John Warren, 3rd Baron de Tabley led him to bookplates, and he completed the reference work of Charlotte Elizabeth Schreiber on playing cards.