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Lithography For Artists. Anon
Читать онлайн.Название Lithography For Artists
Год выпуска 0
isbn 9781528762014
Автор произведения Anon
Жанр Изобразительное искусство, фотография
Издательство Ingram
Some people are forever proclaiming easy ways, shortcuts, and substitutes. As they tell it, royal roads turn off at every corner. They are wrong. There is no royal road to anywhere worth getting to, nor any substitute for a unique thing.
GRINDING A TEXTURE ON THE STONE
A stone with the proper grain is the first requisite for successful chalk drawing.
—HULLMANDEL
We have, however, more to think about, under the general head of “grinding,” than merely texture. Often there is old work to be got off, and always we have to keep the top and bottom parallel. Calipers are used to test this in the shops, but I have easily got along without them. When I start to print, the press itself quickly tells me if the stone is unequal. If one end binds, I compensate by blocking up the other with paper under it—torn of unequal widths and laid to form a slope. Later, when I next grind the stone, I merely put a little extra work on the thick end.
For testing the truth of the plane surface of the stone, a rigid steel straightedge is used, though after some practice one gets along mostly without it. Having got the habit, I now grind a stone true unconsciously. At first I used to test by laying down a hair on the stone, setting the steel on it, and if at any point the hair was not held by the steel, the stone was hollow there and grinding continued. A bit of paper may replace the hair.
Originally sand was the thing used to grind with, but now other substances are also in use—ground flint, ground glass, emery powder and carborundum, among them.
The abrasive is put upon the stone with water and rubbed either with a second stone or with an iron shaped like a grindstone and called a “levigator” or “jigger.” Commercially, stones are commonly surfaced by machinery. A stone may be ground wet or dry. The latter is unusual. If adopted, the surface must be cleaned dry, with brushes and coarse cloths that remove every particle of grinding dust. Senefelder advises soap in the grinding water,—a very bad thing and liable to cause the stone to roll up smutty or grow soiled in the course of printing. A little sugar in the water helps keep the abrasive in an even layer. If a polish is wanted (though you cannot use crayon properly on a polished stone), it is got usually by pumice and Water-of-Ayr stone. This latter stone is known in the American market as “Scotch hones” when in flat slabs and as “snake slips” (“snake” is short for “snake stone”) when in pencil-like prisms. It is a lovely, soft, fine-grained material found on the river Ayr, in Scotland.
Before stone grinding can be carried on in a civilized way, arrangements must be made to catch the slop. A tight box or tank of sufficient size with a couple of pieces of wood—say 2 by 4 inches—laid across the top to put the stone on, really furnishes the main essentials.
A common kitchen article, a sheet-iron roasting pan, has on occasions held a stone for grinding.
When your stand is established, put the stone on, wet it, and mix into water a spoonful or so of abrasive—more if you are using sand than if you are using something harsher. Set the levigator down upon it. Do it care-ally, because the slightest bumping of the heavy iron may crack off minute unnoticed chips liable to plow frightful scratches into the stone. Experience will show you how to spin the levigator about, neither too fast nor too slow; how to add water; when to clear off the old sludge, thick and mucky from ground-up stone; and when to stop. Sand cuts down a stone more slowly than flint, and the latter not so fast as carborundum. Carborundum costs seven times as much as sand and cuts twenty-six times as fast. The coarser the abrasive, the harder the work and the faster the cutting. It is seldom worth while to cut with a sand coarser than will pass a 60-mesh sieve, or a carborundum coarser than number 100. When the old work has been thoroughly removed, put on finer powder—whatever you want, according to your intended drawing. When sand is used, its grains become round and worn down, in which state they yield a flat, poor surface. Toward the end, therefore, put on fresh sand and stop before it loses its tooth.
Delicate variations may be obtained by mixing different sorts of abrasives, by using grinders of different sizes, by substituting a second lithographic stone in place of the levigator (a very usual practice), by the amount of water present, by the amount of muck allowed to accumulate, and even by the variety of the speeds used. When a second stone takes the place of the levigator, a tendency toward convexity must be guarded against in the lower stone. By means of small grinders different parts of the same surface may be given different textures, each suited to that part of the design which it is to receive.
When the grinding is finished, flush the surface very thoroughly with great quantities of clean water. Then set the stone on edge in a clean place to drain and dry. Keep your hands off the surface; also, protect it from dust.
In grinding off old work from a stone, very rich drawings that have carried a deal of ink will need more prolonged grinding than delicate ones. Also, work which has remained weeks or months upon the stone will require to be ground more severely than recent work. In using carborundum, I generally get the necessary results by one grinding of No. 150, followed, in order, with one grinding of each of the successively finer grades, 180, 220, F, FF, stopping at that grade which suits my intended drawing.
Do not let the appearance of old work, after some grinding, unduly intimidate you. It will, or may, show as a pronounced light pattern. If insufficiently ground, this pattern may, as you print, begin to take the ink. Yet it is not always necessary to grind it totally out of existence. I have ground and printed an edition from a stone showing such a pattern of old work, without any harm from it at all.
Avoid grinding in a stiff muck of pulverized stone. Clean off and start anew before you reach this stiff stage. Don’t use too much water just at first: it washes the abrasive off the stone. Don’t use too little water at any time. As the water-film between stones grows thin, there comes a point where a suction action sets in, the stones being squeezed together by atmospheric pressure. Normal textures do not result if such conditions prevail.
I have forgotten to mention the rounding and polishing of the stone’s edges. This is done with powerful rasps, followed by finer ones, finished with a polish got by Water-of-Ayr stone. The purpose of these rounded edges is to prevent chipping, keep paper from creasing, and, much more than all others combined, to keep the ink from sticking to them. Angulak or rough edges insist upon getting inky.
Do not allow anyone to make you believe these technical things are impracticable—they are not. As to time, I can surface an ordinary stone and have it ready to draw on in 15 minutes, not longer than is required to stretch a sheet of water-color paper.
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