BuyEpson (direct from Epson, whole range including rolls)
7dayshop (online, cheaper if you plan in advance)
PC World, Tottenham Court Road opp Warren St or Ryman’s near Goodge St (closest)
Jessops or Jacobs on New Oxford Street (south end of Gower St)
information for all kinds of studio work from all studio areas at the Slade School of Fine Art