Few things are as boring as a piece of art porn that pays penance for its titillating scenes with twice as many dull ones. Silk follows a young, married silk merchant from 19th century France whose business journeys to Japan upend his life in various erotic ways. There are steamy baths and bared courtesans, as well as miles and miles of listless dialogue and dreamy landscapes to make up for them. Michael Pitt plays the merchant (Keira Knightley has a bit part as his wife) and he embodies the drowsy tone of the film. Pitt is a gifted actor, though a specific one – his ephemeral quality was perfect in Gus Van Sant’s Last Days, where he played a ghostly doppelganger for Kurt Cobain, but that same approach doesn’t work here. Pitt isn’t able to anchor Silk, and how could he, when his main talent is the ability to evocatively drift away?