The Invention of Lithography Part 19

The sc.r.a.per is a piece of pear wood as long as the size of the plate demands. Its height is about four inches, its thickness one inch. The end that rests on the leather is trimmed down so that it has a thickness of only one line. This end must be especially true and planed to fit the stone, also neatly rounded off. It should be so fastened to the arm that it may be adjusted to the position of the stone. The stone does not always lie truly horizontal in the press, sometimes because it is not uniformly thick, sometimes because the underlay is not quite even, and sometimes because the press itself has been a little strained. If the sc.r.a.per has been made properly, it will adjust itself to the stone, even if the sc.r.a.per arm is not quite plumb on the stone, a condition that often occurs with small work, such as t.i.tles and other things that are at the end of a stone.

(5) For every press a number of sc.r.a.pers of different dimensions must be in stock. Generally a lever press is so made that the printing-frame can be raised or lowered according to the thickness of the stone. Then the sc.r.a.per must be changed accordingly.

(6) The connection of the upper board with the tread is made by a thin stick that is fastened to a lever below, by means of a small iron piece which contains several holes that serve to adjust the height of the tread according to need.

(7) The leather in the printing-frame is strong calfskin. It must be stretched very evenly and tensely and must be smeared from time to time very thoroughly with tallow.

(8) On the outer side of the frame there are four wooden strips that can be adjusted as desired. One serves to show the point where the impression is to begin. Another shows where it is to end. Both must be so strong that they can resist the sc.r.a.per. The other two are adjusted at the sides and guide the sc.r.a.per.

V

THE CYLINDER PRESSES

When Herr Professor Mitterer installed a lithographic inst.i.tution for the Feyertags-Schule, the lever press appeared to him to demand too much labor, especially when powerful pressures were desired. He invented the so-called Cylinder or Star Press, which has its place in most establishments, especially those in other countries. It has had minor changes made in it by many persons, but on the whole, n.o.body has succeeded in improving it notably, except for a considerable improvement made by Herr Mitterer himself. My description will include this improvement.

The cylinder press might almost be called a reversed lever press. Herr Mitterer borrowed from it the idea of effecting the impression with a sc.r.a.per, but he did not let it move over the plate, as in the lever press. He gave the sc.r.a.per a fixed, immovable position while the stone was drawn through underneath, thus making his press resemble a copper-plate printing-press somewhat.

Ill.u.s.tration number 4 shows this machine in the moment when the impression has been made. In the middle of the machine is a cylinder ten to twelve inches thick and as long as the breadth of the press. It has strong iron spindles that revolve in well-lubricated bra.s.s bearings.

Above the cylinder is a board on which is fastened the stone with the printing-frame. The sc.r.a.per is on a strong lever that is held up by a counterpoise. When everything is ready for printing, the sc.r.a.per is forced down. By means of a strong iron hook it engages the treadle and thus can be pulled down with the utmost tension. Then the cylinder is turned by means of two levers affixed to the crank, and this draws the stone and printing-frame through under the sc.r.a.per. One workman alone can do this under ordinary pressure, but an appliance at the other end of the press enables a second workman to help.

VI

GYRATING Sc.r.a.pER AND DOUBLE LEVER PRESSES

I have already mentioned the gyrating sc.r.a.per press. I have improved it considerably. It has the form of the ordinary lever press, but all the parts can be much lighter. For instance, the lever is only one and a half inches thick. The spring (the elastic board) is very elastic and need exert a pressure of only one hundred pounds. The little sc.r.a.per is only an inch long and presses on the plate with a force of fifty pounds.

The press is useful for very thin stones that might crack under greater pressure. The pressure, nevertheless, is great, because it is all exerted on such a small area. The press has two defects. It is easy to miss many parts of the design with the small sc.r.a.per, and the paper is likely to stick to the leather, producing poor register. I have obviated these faults with the following invention: A large sc.r.a.per is fastened to the lever to press on the plate with a force of one hundred pounds. A small one is fastened to this in such a manner that it can be moved to and fro easily. While one workman rubs to and fro with the small sc.r.a.per, another draws the entire stone and printing-frame slowly along under the large one. If good underlays are used in addition, this process will produce beautiful work that cannot be produced so well with any other machine. However, a large field is left in this form for improvement.

The fact that the concentric motion produced by a single lever can be transformed into an almost straight motion by use of a second lever, led me to design a double lever press, which has turned out very successful, giving great force with speed. As its description would demand much s.p.a.ce, and since on the whole it ranks equally with the improved cylinder press, I offer to send models to those who desire to have everything useful for the art.

VII

THE OTHER STONE PRINTING-PRESSES

The cylinder press of the Chemical Printery in Vienna would, without question, be of excellent service for the art if it were more powerful.

Its construction is as follows: The stone is fastened to a table with the printing-frame which has fine felt instead of leather. To make the impression a bra.s.s cylinder eight inches thick is rolled over it. As this cylinder would not produce enough pressure from itself, despite its ma.s.sive make, two iron beams are fastened to the axles. They pa.s.s through the table and are fastened to a box that contains iron or leaden weights. Unfortunately the s.p.a.ce prevents the use of more than five or six hundredweights, and this is too little for the large surface of the cylinder, thus forbidding any sharp, clear impressions.

This kind of press could be greatly improved if it were built higher to give more room below for weights, or the beams could be lengthened and pa.s.sed through the floor into a lower room, thus giving s.p.a.ce enough to add weights up to fifty and more hundredweight.

The press of Herr Andre is much like this, except that its cylinder is only three inches in diameter and that it is forced on the stone not with weights, but with a lower cylinder that presses upwards. It prints fast, like the other, but does not possess enough power.

In conclusion, I must remark that the concentration of ideas caused by writing this chapter has led me to begin experiments toward making a lithographic press which shall leave nothing to be desired. As soon as my affairs permit, I shall execute this on a large scale, and if the result fulfills my hopes, it will be a pleasure to describe it accurately to all friends of my art, or to furnish them models at cost.

PART II

CONCERNING THE VARIOUS METHODS

There are two princ.i.p.al methods of stone-printing, Relief and Intaglio.

In the former, the fatty parts of the stone are not attacked by the etching fluid, while the rest of the stone is dissolved more or less.

Therefore the fatty places are left in relief.

In the second method, the design is either engraved into the stone with a sharp steel instrument or etched-in with acid.

The relief method has the advantage of greater speed and, generally, a greater number of impressions. It is easy for the artist to apply, especially in crayon work. The intaglio, however, makes possible finer and more powerful work, and again, in many cases, is the easier of the two for the artist. Therefore it is impossible to say in a general way which is the better. It depends on the work to be done.

CHAPTER I

RELIEF METHOD

To this method belong princ.i.p.ally: (_a_) Brush and pen designs; (_b_) the crayon method; (_c_) the transfer method; (_d_) the wood-cut method; (_e_) a sort of sc.r.a.ped style; and (_f_) spatter-work.

I

BRUSH AND PEN WORK

This is one of the best in lithography, and perhaps the best, because it touches daily needs most directly. It can be used not only for all kinds of writings, but also for ill.u.s.tration that does not demand the supreme perfection of copper plate. The ease of manipulation, the speed and the almost countless number of impressions recommend it especially.

It may even be prophesied that in future, when true artists have become better acquainted with it, it will be used for high forms of art.

Much as this method has to recommend it, it has been used mainly for script and music, and it is difficult to gain adherents and followers for it. The reason is an apparently trivial thing, but it has made most artists averse to it. Since stone-printing exists I have found only two persons who could do anything with the steel pen at the first attempt.

These were my brother Klemens, and a Herr p.o.r.ner, who works now in the establishment of Herr Muller in Karlsruhe. All others have had to struggle more or less with this slight trouble, and yet it does not demand more than a few days of patience and study.

For pen work one must not be too particular in selecting stones, as the less perfect ones are more available for this than for any other method.

However, the general rule holds good here, too, that the purest and hardest stones are best.

If they have been used previously, so that the fatty inks have penetrated pretty well, they still need not be ground too deeply, but it will suffice to grind them merely till all depressions and elevations of the previous design have vanished. They may be ground with sand or pumice, so long as they are made smooth so that no roughness can be perceived. The smoother and finer the surface is, the easier will it be to work on it with the pen.

To design well on stone with chemical ink, the stone must be prepared after grinding so that the ink shall not flow and spread. Dissolve one part of tallow in three parts of oil of turpentine and coat the dry stone very quickly. With a clean rag or tissue paper wipe it at once so thoroughly that the coating vanishes again almost entirely, leaving only a thin film that can be easily devoured and removed when the etching fluid is applied later. It is well to do this some hours before beginning work on the stone, partly to give the turpentine odor time to evaporate and partly because it is easier to work after a little while than immediately after coating the stone. The stone can be prepared far in advance, even so long as some months before using. In that case it is necessary merely to clean the dust away with a cloth or fine brush. This should be done anyway at intervals during the work, or it will clog the pen.

I prefer another way of preparing the stone for designing, because it is one that insures the stone against containing any hidden preparation, which can easily occur in grinding owing to carelessness or uncleanliness on the part of the workman, especially if many old plates are being reground, when the gum which most of them contain from previous use will mix with water during grinding and thus form a partial preparation of the stone.

I coat the plate with strong soap-water containing many soapy particles, and dry it off as well as possible. Now, there will be too much alkali on the plate, which will not be good for fine work. I pour a few drops of clean water on the stone, make it quite wet with this and dry it again thoroughly. The fat of the soap will then have precipitated itself on the stone and at the same time has lost all alkali. The soap-water must not be too thin, as in that case it will precipitate too much fat on the plate at once and the etching fluid will not be able later to destroy it properly. This would mean the total destruction of the design. To make quite sure, I advise beginners, after applying soap-water and drying it, to coat the stone with the tallow and turpentine solution, clean it quickly, and thus be absolutely a.s.sured that the plate is thoroughly prepared for the design.

It must not be imagined that this preparation for work is not very important. I am convinced that less depends on the quality of the ink than on a surface freed from all acid and mucous substances and provided with a sufficient amount of fat.

On the stone thus prepared the rough design may be done with lead crayon or red chalk or by tracings or transfers. Any surplus of lead or red chalk would make trouble during the succeeding completion of the design with chemical ink, and must be removed carefully. If the design has been laid on by transfer, the resultant fattiness must be lightly rubbed away with a fine sand, but not so as to injure the design.

This method, of first drafting the design on paper with soft chemical transfer ink and then transferring to stone, offers such advantages that it pays to practice it. Care must be taken to remove all surplus of color, as otherwise all lines that should not appear will resist the etching fluid and gradually show again. Those who fear destruction of the design by the use of sand can effect the same purpose by printing off on clean waste paper a few times, or the design may be printed off on paper before being transferred, thus cleansing it of surplus fat.