Bromoil printing and bromoil transfer

by Emil Mayer

The defatting is therefore a procedure which is advisable in most cases and only after this is the bromoil print actually complete. After it has been carried out, the image consists of pure mineral pigment adhering firmly to the gelatine. It is self-evident that a print treated in such a way is absolutely permanent, provided that the inks used are non-fading, which is almost always the case. One can also subsequently moisten or soak the print without any danger if, for example, it is to be mounted on cardboard.

Retouching the Print.—The defatted bromoil print is susceptible to the most far-reaching mechanical modification. The picture now consists, as already mentioned, entirely of extremely fine particles of pigment adhering to the film about as strongly as the lines of a pencil drawing. This pigment can also now be treated with rubber exactly like a pencil drawing. The ink, as far as it was put on by degrees, can also be removed by degrees from any desired place by proper measures.

In the finished bromoil print the deepest shadows are formed by a comparatively thick layer of pigment, while the lights have only a very delicate coating of ink. We are consequently able to diminish the thickness of the film by proper treatment, removing it layer by layer, so that the shadows become more transparent, or the film of ink may be entirely removed, so that the gelatine base is laid bare.

The best tool for this is a piece of a hard rubber eraser sharpened to a fine point with sandpaper or a file. It is also advisable to use a very soft sharpened eraser for treating very light places.

Every part of the print which is to be lightened should now be gone over with the point of the rubber in fine lines very close together. The ink powder, which is taken up by the rubber, must be removed from time to time by rubbing the rubber on the sandpaper, or it will be left on the print again in the form of dark lines. If gentle rubbing with the eraser does not have the desired effect, it should be used more energetically. Sometimes the ink adheres so firmly that the rubber must be used quite vigorously in order to remove it. On the other hand, where soft ink has been applied, one must work very lightly, or more ink may be removed than is desired.

Important details of the picture may be completely taken out with the rubber without getting down to the paper, if the work is done carefully. Thus, for instance, unsharp figures in the foreground of a street scene, disturbing details in the background of a portrait, undesirable details of a landscape, such as telegraph wires, ugly poles, trees, etc., may be removed almost without leaving a trace behind. If this treatment does leave visible marks, they can be easily made to disappear with brush and ink.

For removing or lightening tiny spots or lines, or for removing brush hairs and similar imperfections left during the inking, one may use a sharp lancet or penknife, or a steel needle set in a handle. Yet in the use of these sharp instruments one must be careful to scrape the surface very gently and carefully, or the gelatine film may be cut, which leaves noticeable marks.

The possibility of removing the ink from the finished print in layers by the use of an eraser, without leaving any trace, gives the bromoil printer another means for modifying the tone values of the print at will. If preconceived ideas were not fully carried out in the application of the ink, because tiny places could not be properly worked out with the brush, or because they were overlooked, the desired change of tone values can now be effected; with the aid of the rubber, also, especially effective lights may be added to the picture.

If, in the application of the ink, large areas were not quite uniformly treated, they can be corrected now without trouble. Dark spots of ink can be easily removed with the rubber, and it is often easier to even out a rather broken surface with the eraser than with the oil-printing brush.

Bare spots, white points, and other defects of the image, or places from which too much ink has been removed with the eraser or penknife, are best spotted with water-color of proper shade, or in the case of brownish-black prints, even with charcoal. The defatted film takes the water-color easily and places treated with it remain perfectly matt; on the other hand, retouching with lead pencil should be avoided whenever possible, as this always produces a certain shininess, which is rendered particularly prominent by the dull surface of the rest of the print. A bromoil print which has not been defatted may also be retouched in the same way, but the parts worked up with the rubber are then noticeable. Filling up spots on such prints is best effected with oil-printing ink, applied with a water-color brush dipped in heavy benzol so as to dilute it.