These conditions induced me to try and prepare the necessary inks myself, and after many trials and exhaustive experimental study of the manufacture of artist oil colors I finally succeeded in reaching my goal.
Inks and Brushes.—My starting point was a great desire to make a hard ink, since I recognized that this consistency was the necessary starting point to be able to use any degree of relief. I further desired to attain a mixture of color and medium which should be as perfectly homogeneous and as fine as possible, and moreover to provide a palette, which should not only satisfy all requirements of the bromoil printer, but also give him only fast colors, perfectly suitable for the transfer process and soluble in benzol.
Command of a hard ink—which can be suitably softened to meet any need—is very necessary to the bromoil printer, if clean shadows are to be obtained. As already mentioned, it has long been known among painters that the colors appear purer and more luminous when they contain as little medium as possible. In order to be able to apply such stiffly ground colors, the painters use bristle brushes, which do not produce the same results as hair brushes. Naturally there is nothing to prevent the bromoil printer from using bristle brushes, only they must fulfil certain requirements. The literature of bromoil printing gives many hints on this point, but I have not been able to locate a practical use of these brushes. Some years ago I had made, by a manufacturer who makes excellent hair brushes for our process, bristle brushes in stag’s foot shape. The result was extraordinarily gratifying. These brushes do not drop their bristles nor do they suffer from the troublesome breaking off of the points, they do not pick up the dust and do not smear even when very soft inks are used, because the bristles, unlike hairs, do not cling together. They can be easily and thoroughly cleaned and are obviously very lasting, and in addition cost only a fraction of what must be paid for really good hair brushes.
As regards the size one is not limited, as with the hair brushes, to small sizes, since the hog’s bristle brushes can be made of any desired diameter, even 10, 15 or 20 cm or more (4, 6 or 8 inches or more) so that the working up of large prints is considerably facilitated.
Two conditions must, however, be carefully observed for good results. First, these brushes must actually be made from the very finest cut bristles and, before they are used, they must be repeatedly and very thoroughly cleaned, because they are very dirty when purchased.
The principal advantage of these brushes is that they enable one to use considerably harder inks than is possible with hair brushes, which results in much greater clearness of the shadows. When this clearness of the shadows is obtained, one can always use a hair brush for working up the finer half-tones and high lights. This is, however, not necessary, at least in the majority of cases.
I have not noticed any disadvantage in the use of these brushes; the gelatine has never been pierced, even in the highest reliefs.
Although I am averse to anything that may smack of advertising, yet I will state here the source of these brushes, because the expert manufacture of these tools, so important in our handicraft, is not found everywhere in equal perfection, and because I believe that it will be of considerable service to those wanting brushes. The brush manufacturer is Magnus Bühler, Wien VII, Breitegasse 4, Austria.
Fig. 3