Wolfgang Moersch Photochemie
Am Heideberg 48
50354 Hürth

Tel.: +49-2233-943137
Fax.: +49-2233-943138


Data protection
Direct iron toning

Select Ivory (PW17)

"What you get is what you see." In contrast to indirect toning, the process of direct toning can be stopped once the desired colour intensity is reached. The disadvantage mentioned earlier in the introduction - the instability of a mixture of toner and bleach substances in an acidic solution - could be widely eliminated in the formulation of MT7. Fibre based paper can be toned with it just as well. Prints will not be ruined by deposits of turnbull blue.

Apart from the three substances that are necessary for the process of toning (potassium ferricyanide, ferric salt and acid), the toner comes with a stabiliser. The ratio in which the substances 1, 2 and 4 have to be mixed is given in the instructions. The dilution with water is variable. Part 3 is the stabiliser. You can add higher amounts of it. In the instructions I recommend to do so depending on the circumstances. The higher the amount of stabiliser, the longer does the toner stay acidic, but the slower will it work. If added excessively it will stop toning completely. You cannot entirely eliminate the formation of turnbull blue dye, but it appears a lot later in a solution with stabiliser than in one without. An early warning sign is a blue deposit on the inner walls of the dish. If this is still soluble, it can swash from there onto both surfaces of the print when tilting the dish.

Once the amount of these deposits increases and the colour of the toner changes to dark blue, you don't need to toss the solution away, but you can filter it. A normal coffee filter is sufficient to get out the blue dye. After use, the toner can be stored in a plastic container. You can go on using it for weeks. There will be a dark deposit on the bottom of the container, which you should try to keep there by pouring out the toner carefully. Alternatively, you can filter before using it.

The toner reaches all densities simultaneously. The transformation is quickly in low silver densities. The higher densities of the shadows take longer to be fully toned. This opens the opportunity to achieve light blue as well as slightly blue-green hues without a significant increase in contrast. It also allows us to tone by vision in a highly diluted working solution, in order to preserve the original tone values or just to achieve a very subtle colour change. A highly diluted solution allows you to observe the toning process. This is an advantage especially if you do not want to tone completely. In a strong working solution warmtone paper is completely toned after 30 seconds and bromide silver paper after 60 to 90 seconds. The speed of toning and the resulting hue can be adjusted by either the degree of dilution, by increasing the amount of stabiliser or by reducing the amount of acid.

When toning directly, if you use a strong working solution all tone values increase in density. If you make sure that the highlights are clear after developing, so that they do not absorb any dye, toning completely can prolong the curve of tone values by one zone. Doing this Dmax values can reach 2.4 logD and above.

In all direct toning methods, the image whites receive a yellowish cast from the ferricyanide of the toner. This cast could be removed completely by thoroughly rinsing the print. This, however, would also attenuate the blue colouring (compare to indirect toning). Fading colours can be prevented by making the rinse water slightly acidic, but this effort is a time consuming procedure. A 1- 2% saline solution removes the yellow cast within 2 to 3 minutes. Sodium chloride-powder with sodium citrate is included in delivery of the toner. With this you can prepare a stock solution, which is to be diluted 1+9 to 1+14 for use.

Select VC (PW14)
This is the typical light blue tone of warmtone paper in normal configuration of the toner.
You can see clearly, that the delineation in the highlights - adequate for the untoned print - is already too dense for iron toning. Prints should have brighter highlights before toning in iron.

© Serhan Sözmen

Select VC semi-matte (PW15)
The print was split to show the effect of different toner configurations and times of toning:

left - normal configuration toned for 50 seconds

right - twice diluted, twice the amount of stabiliser, also toned for 50 seconds

Select VC (PW14)
The influence of the developer that you use is more obvious on warmtone paper than on neutral-tone paper. The warmer the initial tone the greener the toning result.

You can achieve a colour shift to delft blue by placing the print in an alkaline after-treatment bath. Whether you use borax, sodium carbonate or ammonia is less important than the content of alkalinity and the duration of the print in the bath.

50ml of ammonia (10% solution) are included in delivery of the MT7. Add between 0.5 and 1ml to 100ml of water and treat a print for 20 to 90 seconds.

© Frank Peinemann

You will observe an immediate colour shift towards purple. This should not make you stop treatment too soon. If you stop too early the tone can shift back towards its initial colour while rinsing. You only may have left the print in the solution for too long, if the highlights lose their colour completely - and with this their density. In the subsequent rinse water the alkalinity of the print is not instantly neutralized. Already slightly alkaline tap water can have a reducing effect on the colour after 5 minutes of rinsing. However, longer rinsing - like after fixing - is dispensable here.

If the colour faded more than expected during after-treatment or rinsing, you can regain the initial image tone with slightly reduced intensity and density by treating the print in a slightly acidic water bath. To preserve the gloss of the surface, I recommend the use of organic acids like citric- or acetic acid over mineral acids.

This example is to compare the effects of direct and indirect iron toning: both photographs are on the same paper, were bleached in oxalate bleach and toned in ammonia ferric sulphate. The one to the left was exposed to diffuse indoor daylight for 3 hours. The one to the right was exposed to 6 hours of direct sunlight. This darkening is due to incomplete conversion of the silver image to a dye image (compare to indirect toning). It has to be taken into account when toning. Even with this darkening effect, you will not reach the maximum black of a print that has been toned directly.

If you are not pleased with your toning result - irrespective of the method and formulation you used - you can redevelop the silver image in any given positive developer.

This redevelopment, however, usually comes with strong yellowing of the image whites. As is shown to the left, this does not necessarily mean that the print is lost. The yellow cast can easily be removed in an acidic bath. You can use an organic acid like (freshly prepared) acetic or citric stop bath to de-fog the print.

Already after 30 seconds of treatment, the yellow cast is cleared. A print that has been saved this way can be toned again.

toned in standard configuration
400ml of water
part 1 to part 4 10ml each

toned for 40 seconds

The hue is blue-green. The shadows are intensified.

If a pure blue tone is desired, you have to give the print extra treatment in an alkaline bath.

Toned as above + bathed in borax for 1 minute

If you want to reduce the colour saturation of warmtone paper already when toning, you can fourfold the amount of stabiliser.

400ml of water
Part 1 - 10ml
Part 2 - 10ml
Part 3 - 40ml
Part 4 - 10ml

toned for 40 seconds

Fomabrom Variant III
standard configuration
toned for 1 minute

All densities increase, especially those in the shadow areas.

After-treatment in ammonia alkaline solution for 1 minute
(2ml of a 10% solution of ammonia on 200ml of water)

Ilford MG Warmton
standard configuration

toned for 90 seconds

After-treatment in a weak ammonia alkaline solution for 2 minutes (1ml of a 10% solution of ammonia on 400ml of water).

Configuration as above, but only toned for 30 seconds

After-treatment in an ammonia alkaline solution for 50 seconds
(2ml of a 10% solution of ammonia on 200ml of water).

© Peter Specht

Fotokemika EMAKS
Adox Nuance

toner configuration 10+10+10+10+1000ml
toned for 90 seconds

In diluted toner this paper only shows a subtle tint in the highlights This is due to its high content of silver.

Even in standard configuration the complete transformation of the silver to dye takes longer than 2 minutes.

© Helga Pisters

Fotokemika Varicon
Adox Fine Print Classic VC

configuration 10+10+30+10+500ml
toned for 30 seconds

Below left:
configuration 10+10+5+10+500ml
toned for 90 seconds

Below right:
After-treatment in an alkaline solution for 60 seconds to change the tone to delft-blue (2ml of a 10% solution of ammonia on 200 ml of water).

Kentmere Fineprint VC
Left: normal development
Below for comparison: in lith development

Both prints in identical toner configuration

Left: toned for 45 seconds
Below: toned for 75 seconds

To completely tone the dense shadows of a lithprint, you need longer times of toning.

If you plan to tone your lith print in iron, you should not develop it to maximum black - as was done here. The densities of the stark lith shadows increase immensely and adjacent zones turn maximum black as well.

As it was taken in diffuse light, the negative above, would have been a better choice for a blue toned lith print.

Ilford MG IV toned for 40 seconds

treated in a 0.2% solution of ammonia

MCC two bath development, first bath lith
configuration 10+10+20+10+400ml, toned for 60 seconds

Toned to delft-blue in a 0.2% solution of ammonia for 75 seconds