This is a 1 liter bottle of Harman Selenium Toner from Ilford. It is another innovation by Ilford Photographic, a leader in the film/chemical industry. This toner provides rich and deep blacks with a tendency to push color towards the purplish end of the spectrum. Olive hues will be absorbed yielding brown tones on fiber-based silver paper.
Selenium toned prints have a subtle look that no other type of toner can yield; Dmax is enhanced with a corresponding "bump" of print quality
Toxic - Must be handled in a well ventilated area and treated as hazardous waste
Multigrade Warmtone papers are very responsive to selenium toners: using higher dilutions (e.g.: 1+10, 1+20) gives a slight cooling of the image tone and a shift in hue towards red; When you use at lower dilutions (e.g.: 1+3, 1+5), you can get a purplish brown
Colder papers react less rapidly, but they still benefit from selenium toning's highly effective deepening of the maximum black and its expansion of the entire tonal range; The reaction of selenium on the silver halide (AgX) of the print hardens the adherence of the image to the paper; This improves the chemical stability of the print as well as its permanence and archival properties while also defining its appearance
For a standard dilution of 1+3, the capacity of the toning solution is at least the equivalent of 25 sheets of 20.3x25.4cm (8x10") per liter
Working strength solutions will normally last for up to 6 months in full, tightly capped bottles, 1 month in half tightly capped bottles, and up to 7 days in an open tray