Lithography

The art of printing hy a chemical process from designs made with a greasy material upon stone.

“The discovery of this art is due to Aloysius Senefelder, a.d. 1800, and rests upon the following properties of the substance forming the printing surface.

1. That a drawing made upon it with fat ink adheres so strongly as to require mechanical force to remove it.
2. That the parts of it free from the drawing receive, retain, and absorb water.
3. That a roller or other instrument being covered with fat ink, being applied to the printing surface when inked and wetted, the ink will attach itself only to the drawn parts, and will be repelled fi-om the wetted parts.

Plates of zinc have been treated by this process in the same w ay as stone, and the process is then called ‘zincography.’ By this process it will be seen that a drawing being made or an impression taken upon paper with prepared ink, and transferred by pressure to the stone, &c., the latter will form a printing surface, from which fac similes of the drawing or impression may be obtained by this process.”*

The following are the chief circumstances connected with the early history of the art of lithography.

“Aloysius Senefelder produced a piece of music, his first impression from stone, in 1796. He secured a patent for it in 1800 in several German States, extending over fifteen years. It was introduced into England in 1801, and he published a work on the subject in 1817. A partnership was entered into and establishments were formed in London and Paris in 1799, but they did not succeed. Another at Munich, in 1806, was more prosperous, and the inventor was ultimately appointed to the Inspectorship of the Royal Lithographic Establishment in October, 1809. The Society for the Encouragement of Arts in London voted Senefelder their gold medal in 1809.”†

The stone best calculated for lithographic purposes is a sort of calcareous slate found on the banks of the Danube, in Bavaria, the finest being found near Munich. A good stone is porous, yet brittle, of a pale and yellowish drab, and sometimes of a grey neutral tint. The stones are formed into slabs from one and a-half to three inches in thickness. To prepare them for use, two stones are placed face to face, with some fine sifted sand between them, and then are rubbed together with a circular motion to produce the requisite granulation, which is made fine or coarse to suit the purpose of the artist.

The principal agents used for making designs on stone are called lithographic chalk and lithographic ink. They are composed of tallow, virgin wax, hard tallow soap, shellac, sometimes a little mastic or copal, and enough lampblack to impart a colour to the wax. These ingredients are put into an iron saucepan, and exposed to a strong fire until the mass is in a state of ignition. When the quantity is reduced one-half, the pan is carefully covered, or put into water to extinguish the flame and cool the mixture. After being well worked up, it is formed into small cakes or sticks. The ingredients are the same in the chalk and the ink, but the proportions are varied, and a little Venice turpentine is often added to the latter. The chalk is used in a dry state, but the ink is dissolved by rubbing in water, and is used in a pen or with a camel’s hair pencil. The presence of soap renders it soluble in water.

The artist completes a drawing with the chalk upon a grained stone as he would make a drawing in pencil or chalk upon paper. If while in this state a wet sponge were passed over the face of the stone the drawing would wash off. To prevent this, and to make it capable of yielding impressions, a weak solution of nitric acid is poured over it, which unites with and neutralises the alkali or soap contained in the chalk and renders it insoluble in water. After this the usual course is to float a solution of gum over the whole face of the stone, and, when this is taken off, the drawing is no longer removeable by the application of a wet sponge, because the chalk is now insoluble.

The stone is now ready for the printer, who obtains impressions by the following process. Having damped the surface of the stone equally with a sponge filled with water which has been slightly tinctured by acid, the printer finds that the water has been imbibed by only those parts of the stone which are not occupied by the drawing, which, being greasy, repels the water and remains dry. A roller, covered with ink, is now passed over the stone, which will not even be soiled where it is wet, from the antipathy of oil and water. But the parts occupied by the drawing, being dry and greasy, have an affinity for the printing ink, which therefore leaves the roller and attaches itself to the drawing. In this state it is said to be charged, or rolled in. A sheet of damped paper is then put over it, and the whole being passed through a press the printing ink is transferred from the stone to the paper, and the impression is obtained. Great nicety is requisite in the preparation of all the agents employed in this art, and in the process of printing, as well as in making the drawing on the stone.‡