You don't smell the slightly fishy odor frm the natural sepia pigment on the internet.
Sepia being composed mostly of mollusc melanin, has the same color as the principal human skin brown pigment. Anything but sluggish, cuttlefish are the action painting metaphors that art needed.
Authentic sepia ink is prepared from the dried ink sacs of the common cuttlefish, Sepia officinalis. Being a naturally derived organic colorants, the pigment is usually considered as not lightfast. But that's proved wrong as shown in these tests.