Introduction
Many B&W images may become more interesting varying their colours by means of toning.
The toning contributes to turn the image to be particularly evocative; sometimes the desired effect may be achieved by means of a simple and subtle variation of its hue so that the image is transformed from a dull one into an attractive image. The colour of a toned image depends on the type of chosen toning, but a toning may offer a number of variations of its main hue, with different effects depending on the paper brand used. Some tonings may change their hue depending on their dilution.
The toning helps to re-create the atmosphere and the magic moment of the original scene: the cool and impersonal objects, like abstract drawings, glass, ice, marine or snow landscapes, stones, nocturnal scenes are best rendered with a blue toning.
The tonings giving brown and reddish hues help to render at best the warm hues of the skin, and are often used for portraits.
A toning with a warm brown hue over a creamy paper gives a genuine sensation of colour and lightness in every image containing a sun ray.
The toning is a technique able to improve a picture, but naturally there is not the need to treat in this way an image if it does not give an effective improving. The toning is the transformation of the metallic silver into a coloured chemical substance. You can start with a picture on B&W paper, cloth, heavy paper, slide, both in form of positive or negative. There are four types of toning:
By means of all the toning techniques one can work in ambient light, except the case of the straight use of the chromogen development to obtain monochromatic slides, because this process must be performed in the dark or in a tank. The images to be toned, sepia excluded, must be slightly overexposed and underdeveloped; this because the toning tends to enhance the hues of the images. If an image is right or contrasted, the results will be less fine because of the too deep shadows. Using the tonings, you need a good ventilation of your room: some products, like sulphides, ammonia, etc. give rise to unpleasant or irritating odours and some has the power of stain the photographic materials. The use of the tonings is not so critical as for the developers, and a temperature over 20°C works well, keeping in mind that the high the temperature the more rapid will be the process and the highlights will be clean. To obtain a uniform toning it is advisable to wet the print for about 5 minutes. You must be sure that the toning solution uniformly covers the prints, and after having reached the desired hue it is advisable to perform a long soak in running water (this also depends from the type of the paper).
History of the toning
The toning of the B&W prints is a technique transforming the greyscale of the image in a monochromatic hue scale. The photographers usually deem it a creative intervention, aiming at giving a more apparent artistic quality to the monochromatic image; they are right, because their toned prints will last longer. This is the less known aspect of some particular tonings. The pictures as objects, the negatives, the slides etc. are modified by the time because some physico-chemical changes damage the image and destroy it. The causes are so many: bad treatment (fixing, washing), prolonged exposition to the light, contact with air pollution, etc.. The photographic image is made of metallic silver grains in a gelatine matrix; the silver undergoes all the chemical transformations of a common silver object (in particular the oxidation which helps the combination with other elements); the gelatine tends to decompose like all the organic matters, included the paper supporting it. The silver is oxidized by contact with air, and if this is polluted it can be transformed and the image fades in short time. Some tonings convert the silver in coloured compounds much more stable, like the platinum and gold ones; these treatments, often used a century ago, today are scarcely found because of the high cost of the chemicals. The platinum treatment is deemed ideal for the conservation of the pictures, also because it keeps unaltered the gray and black tones. This is because the toning is deemed an elixir of life for our prints.
The treatment of the prints
The prints to be toned must ever be well printed (except the sepia toning), passed in a common stop bath, and then well fixed with the double bath technique. Let follow an hypo cleaner bath and then a long soaking, so that the print do not hold residuals of the fixer; these could give unaesthetic spots, hard to eliminate. Ever make some copies as backups: error, spot, scratch on the emulsion are ever laying a snare. Handle with care the print immersed in the toning solution, avoid to touch it with the pliers or with your hands; a scratch or a small fold, and your work will be lost. Protect your hands with rubber gloves when you handle the toners, because the solutions are harmful and irritating for the skin.
The paper
All the photographic papers are OK, and also the films may be treated. Baryta paper, heavy paper, cloth, RC paper: all are OK, but some are better. The baryta papers are the best, but they need a long soaking; the RC papers are easier to treat (both glossy and mat), but the hue will be less fine. They have the advantage of being easier to wash and are able to tolerate the ill-treatment; for the retouching of small spots and dots we can use common felt-tip pens.
Multiple tonings
If we want to give a combo of colours on the same print, we may experiment the selective or the multiple toning. The first process consists in toning only some parts of the print, whilst other are protected by an appropriate coating (arabic gum, cocoa butter, adhesive tape, etc.). The multiple toning, instead, consists in a selective toning with more than one hue. You can make various colours by means of the action of a toner on a image which was toned with a different colour. As an example, a blue toned zone can be shifted to dark green though a yellow toner. In addition to the toners, you will need also a set of brushes, in various sizes, some Q-tips, blotting paper and a lot of patience to be able to work with this technique. Pay attention to not go out of the borders if these are not protected with a coating, otherwise you would develop a gain with a concentrated developer, or you will have a lot of dots. All the toned zones can be developed again, that is brought back to B&W only losing some contrast, but not the sepia tone as it is the higly insoluble and very stable silver sulphide.
How to perform a toning