Foma Fomatoner Indigo is a liquid concentrate, two-bath sulfide-based toner for resin-coated or fiber-based black and white papers. It gives black and white prints a cool, blue tone.
Toning occurs at room temperature (20-25 °C) and the length of time depends on the desired effect, but is generally from 1 to 5 min. One set is enough to tone about 2 sq m of paper, or about 40 sheets size 8x10" /20.3 x 25.4 cm.
The toner is composed of 2 parts (bleaching solution A and toning solution B), each of which is diluted with water in a ratio of 1:2 to optimally control image tone and toning speed. Water of low hardness, preferably distilled, is recommended.
After being washed, prints are first put into the bleaching bath, then washed again and placed in the toning bath. Following toning, prints should be washed thoroughly again, preferably in running water.