As different developers change the tone of a print the process can be changed even further by the use of toners, this not only has aesthetic qualities but greatly improves the archival permanence of a print as can been seen from old sepia toned prints from 100 years ago. Two bath Sepia (thiocarbamide) is my toner of choice. Mixed from raw chemicals, the ratio and dilution at which these chemicals are mixed can be used to produce tones from purple-brown to yellow-brown and some interesting results can be obtained by multiple toning. The density of tone in a print is determined by how long the print is bleached back in the toner bleach (first bath) when the required reduction is achieved the print is pulled from the bleach, rinsed and then placed in the Sepia (second bath) the image will then return to its full density with tone in the areas affected by the bleach. I also like to give the print a brief tone in selenium toner as a final stage as it just warms the image nicely.