Toning in MT4 Polysulphide Toner with additional toning in rinse water If the toner is highly diluted, the print will be multicoloured after rinsing and drying. The warmer the development of the print prior to toning and the higher the dilution of the toner, the more colour you get. The final result is only to be judged when the print is dry. One of the best papers for this toning method is Fomatone. Step 1: Two bath Lith+Catechol - dilution: Lith 1+10, Catechol 1+100 - developed for 2:30 minutes respectively.
	Step 2: MT4 Siena Polysulphide Toner - dilution 1+250 - toned for 20 seconds. The shadows and mid tones turn darker, but the print is still monochrome. If you want this to stay, normal rinsing is not sufficient to stop the toning process. The toner in the emulsion has to be displaced by a 10 to 20% sulphite solution.
	Step 3: After toning, the print is placed in a water bath for 1 to 4 minutes. Even if it is not immediately visible, the toner is still active. Rinse thoroughly afterwards. The toner will be active in the water bath and the early rinse water. After 10 to 20 minutes a completely different image tone can be the result. Highlights appear yellow, transition to the shadows look greenish, or like here blue. Generally speaking, when drying this effect intensifies or it even only generates through drying.

If you increase exposure and adjust the developer dilution or add some alkali to the second developer, the colour of polychrome prints will become more red. When toning in polysulphide, the redder the original print, the bluer will the toned print be (after drying).

Longer development times in the first developer have an even stronger effect, if the developer was retarded by either Lith D or potassium bromide due to longer exposure times.

The dilution of the toner also has an effect on the result. For polychrome prints, MT4 can be diluted from 1+20 to 1+1000. Irrespective of the dilution, the print will be multicoloured. You see this at the latest when it is dry. With higher dilutions and toning times between 1 and 2 minutes, you have more control over the toning process than with dilutions of up to 1+50. Toning will progress in the rinse water in any case. Given that this toner still works in a dilution of up to 1+1000, it is obvious, that the first rinse water is merely only diluting the toner that is still present in the paper. It is not washed out immediately. If you want the print to keep the colour it has right after toning, you have to replace the sulphide in the emulsion with sulphite. To achieve this, rinse the print for only 2 to 4 minutes and then place it into a 10 to 15% solution of sodium sulphite for 2 to 3 minutes. If pure sulphite is not available, use a sulphite-based clearing agent diluted to 1+1.

For demonstration a print was toned for 50 seconds in MT4 Polysulphide Toner 1+25, rinsed for 3 minutes, stopped in 10% sulphite for 2 minutes, and rinsed again. Even after drying, the print stayed unchanged compared to the one that came straight out of the sulphite bath. So the image tone has to look like this (to the left), in order to become a split coloured print by leaving it in the first rinse water for additional toning. The alteration in colour comes along with an increase in density that goes up as far as the highlights. Now the print does not show contrast. The shadows are too dense and to wide. If additional toning in the rinse water had been permitted, the contrast would have increased and mid tones and highlights would have become brighter with a yellow-green cast.

This polychrome print on Select VC was toned in a dilution of 1+1000(!) for only 20 seconds and stayed in water for around 5 minutes before it was rinsed in running water. To achieve this kind of colour split, you need a print with greenish shadows and magenta-red highlights. If the shadows are to appear lighter, development in the lith developer must be stopped prior to reaching deeper blacks. The print has to be soft and delicate. Contrast is given by the toner. Below left: Polychrome print on Kentmere Kentona Below right: toned in MT4 Polysulphide Toner 1+25 for 30 seconds © A.S.C.

Polychrome print on Fomatone

toned in MT4 Polysulphide Toner 1+25 for 30 seconds

This example clarifies how the choice of developer influences the result after toning. By blending it with VGT-A, the lith developer is eased down. This results in another split between shadows and mid tones. Compared to polychrome prints with Lith and Siena, the toned print will be more uniform in colours. This print was also kept in water for additional toning, resulting in a colour shift from originally dark-brown towards yellow. The transition towards the shadows with a trace of green - typically found on lith prints - is barely existent but can be removed with selenium toner.