We generally distinguish two kinds of reproduction:—
(a.) Those from line drawings, in which a negative is made without the interposition of a cross-lined screen, and for which no other means is used for the production of a grain, and
(b.) Those from wash-drawings, paintings, photographs from nature, etc., in which reproductions the half-tones are either broken up into lines or points by the use of the screen when making the negative, or by any of the other above-mentioned means after making the negative.
(A.) LINE DRAWINGS.
By the first method the drawing must be prepared according to certain formula if a good negative is to be obtained which shall not require much after work and disadvantages for photo-lithography. A poor original may cause a partial or complete failure of the work, or at least cause much cost and waste of time; therefore it appears advisable to pay the necessary attention to the original which is to be reproduced.
What a line drawing must possess which should be reproduced well by photo-lithography in order to give a good transfer on to stone we will now point out.
Before all things should be noted that the paper must be pure white and smooth, yet not strongly reflective and not too weak. Smooth white cards of medium thickness are the best to use. Since all lines of the drawing appear in the impression of the same colour, there is not only no purpose, but it may even be very disadvantageous to the reproduction when the draughtsman, in order to increase the artistic effect of his work, or to produce good perspective, etc., draws fine lines or other points in a lighter colour. The striving of the artist for effect, perspective, etc., so far as this is attained by lines or parts of a lighter colour, has for this process of reproduction no advantage, but, indeed, the disadvantage that by this the subsequent manipulations are rendered more difficult, the whole work will turn out more costly and finally less satisfactory.
Although from the present position of photography drawings in any desired colour can be reproduced, yet it is most advantageous if the originals for photo-lithographic reproduction are drawn with fine black matt ink on smooth white papers, and the principal point to which attention should be directed is that all lines, even the finest, should be a good black, and should be kept of the same strength of colour as the other parts of the drawing. The thick lines must be quite filled up like the shadow lines of a strong letter. Shading must be obtained by strong, fine running lines quite separate from one another. In this the single black lines must not be too strong, and the white spaces in between must not be too narrow, or otherwise when reduced in size the white interstices will disappear and will finally form a solid tone. The laying on of a tone or wash is not permissible, as even a light tone will appear in the reproduction as a black spot. It is not permissible also to draw on the same original with inks of different blackness or consistency, and even if a coloured ink be used the whole original must be prepared with one colour (red, dark blue, green, or brown), and that as intense as possible. When we start from the only true standpoint, that every reproduction should be a reflex of the original as true as possible, artistic effects have from this point of view no purpose, since the printer in printing with {22} one ink is not in a position to give grey lines as well as black, but can only give the appearance of everything in one colour only. He is, however, able to give with the strongest line the finest with their own characteristics, and can, therefore, in this direction attain the tonality of the original.
It is obviously, therefore, the artist’s duty to draw in one colour, and since for photographic reproduction black is the best, that is to say Chinese ink, he will do well to completely lay on one side all other artistic materials or effects. At the same time it should be noted that originals drawn in any other colour can be reproduced by photo-lithography, but if the drawing is to serve no other purpose than for reproduction it is best to prepare it in black.
A further important requirement is that the drawing be sharply and cleanly worked, and since the reproduction of a ragged or broken line cannot make a full smooth beautifully running line, they will appear in the reproduction in the same defective way, and then require at least tedious retouching or make the printing of the subject actually impossible. If it is necessary to cross the lines in the shadows this must be done with great care. The points of crossing must be clean and sharp, and the ink must not run. Too close or too frequent crossing of the lines should be avoided, and would produce a bad and different effect in the reproduction. Smudges or wrinkles in the original appear in the reproduction more intense and more vigorous, and therefore it must not be forgotten to carefully avoid these, also any tracing lines must be erased, without, however, damaging the ink lines or rubbing up of the paper.