Fotospeed ST20 Odorless Vario Sepia Toner can produce a wide range of sepia tones on Fibre and Resin Coated B&W papers. It comprises three parts : Part 1 - Bleach; Part 2 - Toner; Part 3 - Toner Additive. Parts 1 and 2 mix separately to make two working solutions with Part 3 being added in it's concentrated form to Part 2 working solution to adjust the shade of sepia required. Part 3 is needed to activate the toner.