Stones to be treated to a tint in this manner must be etched somewhat deeper than others, because the lines do not appear so dark against a tone.
In all intaglio methods there is the advantage that parts that turn out too dark can be modified by fine scraping or grinding. The stone merely must be rubbed with acid-proof ink beforehand, that the necessary preparation of the corrected places with aquafortis or phosphoric acid and gum may not attack the rest of the design. Those who attain skill in scraping or grinding with a small piece of black slate can make the softest gradations of shade in uniformly etched designs, and more easily and quickly than by drawing or coating and etching. If the stone has been rubbed-in with color for the first time only a short time previously, the ground or scraped surfaces do not even need to be etched. It is sufficient to wash them with a rag wetted in gum solution, because the color will not have penetrated the stone so deeply that it is likely to reappear.
If a little dissolved gum is painted on a clean stone that then is inked over its whole surface with printing-ink, none will adhere where the gum is. In other words, the stone will have been prepared there. If the gum is permitted to dry before the ink is applied, those parts will become black, too; but as soon as a few drops of water are poured on and the ink-roller passes over the stone, all the gummed parts will show up white at once. This led me to make a color mixed with gum, with which one can design on stone and that would have the property of preparing it so that, on printing, the design or inscription will print white.
Some drops of gum arabic dissolved in water are mixed with an equal amount of lampblack and rubbed very fine. This makes an ink similar to Chinese ink, and keeps well when dried. It is rubbed down in a saucer with a little water and then is ready for use.
It can be used on a clean stone, but is likely to flow, for which reason the stone must be painted with a little weak aquafortis mixed with a little nutgall, and then well cleaned again. Still better is it to paint a clean stone some days before with oil of turpentine which is cleaned off again immediately. In that case, however, it is well to mix a little phosphoric acid into the drawing-ink, that the designed parts will be prepared the more surely.
When the design is dry, the whole stone is inked with printing-color, care being taken that not a drop of water touches it before it is perfectly black. Then a little water is poured on, after which there must be a little more rolling with the ink-roller till all the design that is drawn with the preparing-ink is very white and clean. Now the stone can be used for printing, being used in the manner used for pen work. To make the design more durable, that it may not in time thicken in its finer parts, the stone may be well inked-in with acid-proof ink and after a few hours, during which it draws together well, the drawing is etched in intaglio with aquafortis. Then it is coated with gum and the printing is not likely to damage the design.
Here we have an intaglio design which is prepared and prints white.
The case may be reversed, and the black plate may be made white again while the design will print black. This is because a stone treated with preparing-ink gives almost the same result, once it is grounded with acid-proof ink and etched as if the design had been engraved into etching-ground. The etched lines need simply be filled with chemical ink as in engraved work, to make them take color instead of coating them with gum. Then there remains only the obstacle that the stone is not prepared over its whole surface and takes color everywhere. However, it is not difficult to clean the plate and prepare it perfectly, especially if the stone is finely polished. It must be rubbed well with color, and wiped clean at once without rubbing too much of it away from the etched design. To make the color easier to wipe out, Frankfurter black and tallow may be mixed in it. Then the rag that has been used for inking-in is dipped into a mixture of twenty parts water, two parts gum, and one part aquafortis, or better still, phosphoric acid, and rubbed back and forth. The rag must not be too dirty and heavy with color, but it must contain some so that the delicate parts of the design shall not be wiped out and thus rendered susceptible to the acid. The next thing is to try with the finger to see whether the color on top can be easily rubbed away or not. In the latter case the wiping must be repeated till the cleansing mixture has so far prepared the surface that the wet hand or a wet piece of leather can cleanse it perfectly and free it from the dark tone. Now the stone is inked-in with firmer color (acid-proof ink is best). This is wiped off again thoroughly. Very weak aquafortis (or phosphoric acid if it has been used for the work) is then poured over it a few times, and this generally prepares it so well that it can be inked and cleaned easily during the printing.
This method is useful for many kinds of art, and it must not be imagined that it is superfluous because the other ways are quicker.
The engraving-needle is very good for drawing the finer parts of the design through the etching-ground, but the coarser ones cause much trouble, while with the pen, these are the very ones that are easiest to produce. By using this method, both advantages can be combined and only that is drawn with the pen which is most readily produced that way.
Thus the whole design, with the exception of the finest parts, is drawn on the white plate with the black preparing ink touche. Then, when it has been covered with acid-proof ink and made white, the finer parts are worked-in with the needle. Or they may be left till the end, when they are engraved-in.
For grounding or blackening the plate, one may use a substitute for the acid-proof ink if the ground is to be firmer. Use the etching-ground (mentioned several times before) of wax, mastic, pitch, and resin, dissolved in oil of turpentine and mixed with fine lampblack. It will then be susceptible of being laid beautifully uniform on the stone with the ink-roller like printing-ink.
The spattered aquatint method resembles this.
The outlines of the design are engraved or etched into the stone very delicately. After rubbing-in with black printing-ink and cleaning again thoroughly, it is rinsed with a great deal of clean water to take away every trace of gum. When it is dry a small brush is dipped into the preparing-ink, and the stone is spattered as described in the article on spatter-work. After drying, the dots that are too large are treated with the needle, and missing ones are drawn in with the pen. Now apply the roller with the dissolved etching-ground, that must, however, have only enough color so that the outlines of the design can show through it. Then the spattered work is brought out by rolling with water. Now coat the lighter parts of the design and etch. Coat again and etch again, in short do as already described for the method of successive etching till the required gradations of shade have been attained. Then proceed as usual with the inking-in and printing.
Any one who has the necessary appliances of the copper-plate worker for making the aquatint ground used by them, and who has the necessary skill, can do so, although the stone is endangered by the heat, and the process is not advisable. The stone is dusted with fine resin. A flame ofspirits is applied below until the stone is so hot that the resin melts and forms the ground.
Better is that copper-plate method in which the resin is dissolved in highly rectified spirits of wine and poured quickly over the whole stone. By breathing on this, the resin is made to separate from the spirits and form tiny pellets, which thus make the required aquatint ground.
Both methods are better for very coarse work than for fine designs. Etching-ground, dissolved in oil of turpentine, or consisting simply of tallow and put on the stone very uniformly with a cotton ball, is much better, and produces an effect similar to wash drawing. However, it is better suited to the lighter parts of a design, because it will bear long and powerful etching only if one hits exactly the proper proportions between ground and etching fluid. Therefore, it is well, after the first tones have been etched and printed, to spatter cautiously with chemical ink all those parts that are to be darker than half-tones. Thus these dots will prepare the design so well at those places that they can withstand the most powerful etching.
This is a sort of middle process between aquatint and the scraped style. It has the advantage of great speediness.
A stone that has been grained for crayon work is coated with the black or red gum ground described for the engraved method, but without previous etching, which would not do harm but is unnecessary. The outlines are drawn in with the needle very lightly, because they are to serve only to make the design visible. Those lines, however, that are not to disappear in the aquatint tone, but are to show plainly, must be cut as deeply as necessary for greater or lesser blackness. Then the stone is rubbed with color and washed with water as in the engraved method.
When it is entirely clean and dry, all the design will be black and the stone white. The design must be examined carefully, and the various gradations of shading should be separated in the mind into about eight leadingclasses, of which four are numbered upwards to the lightest parts, and four numbered downwards to the darkest. Everything in the category of the four dark parts now is worked strongly with chemical crayon. The purpose is to mass a number of evenly separated points over these parts of the design that shall withstand the etching fluid like an aquatint ground, between which the etching fluid may eat the stone and thus form a coarser grain than could be attained merely by rough grinding.
Then the four lighter parts must be coated with chemical ink. The very lightest parts, and all that is to remain white, must be left white on the plate and neither touched with crayon or ink.
Then the stone is etched for the first time. Following this pour clean water over it and let it dry. Then of the four dark parts the lightest are coated with chemical ink, and when it is dry the etching fluid is applied again. After washing and drying, the next lighter portions of the dark sections are coated, and so on till at last the very darkest shadows have been coated. Then a clean brush is dipped into gum solution and everything that should remain white is painted.
If a little oil of turpentine is now poured on the stone, and the crayon and chemical ink are dissolved and wiped off, the stone can be inked with soft inking-color and wiped again with a woolen rag. Then the design will look as if a black veil were over it, because the lightest parts of it and the half-shadows are not worked out at all. Wet a rag with gum solution and a little phosphoric acid, and hold it in one hand while with a fine scraper you scrape in the lights according to their gradation or grind them in with a fine stone, for instance, a slate pencil. As you scrape wipe over the design with the wet rag; and you will see exactly what you are doing as the various gradations will appear bit by bit. The printing in this as in other aquatint methods is done with soft and thin printing-color, and the paper may be more dampened than in other forms of lithography. The press needs considerable tension and the stones must be thick.
The difficulty of getting impressions from crayon that shall not differ from the original design on the stone led me to consider the use of the grained style of the copper-plate engravers. A crayon-like design in intaglio would have a greater strength in the dark parts and greater delicacy in the lighter; be more durable and more easily corrected. I saw at once that if I could attain some perfection, it would mean a great step forward in color printing, also. Thus there were originated the following two processes, which no doubt will in time interest artists to a high degree.
A stone grained for crayon work is prepared with aquafortis and gum. Then it is cleansed with water and covered with etching-ground when dry, as is prescribed for the etched process. The ground must be laid on so thinly and evenly that the design can be put in easily and that it still will resist the etching.
When the stone is cold and the outlines of the design have been traced on it, a scraper of the best steel is used to scrape in the lights and shadows. The scraper touches only the most elevated points of the grained surface at first, and produces larger points only after continued work, just as chemical crayon does. When the whole stone is finished, it is etched as in the etched process and then cleansed and printed in the same way.
If the stone is etched a little more strongly in all its gradations, it can afterward be ground down gently with very soft pumice, or, better still, with black slate and a gum solution, once it has been rubbed-in with color. This destroys all roughnesses that may remain from the first manipulations. Parts that have turned out too dark can be lightened by this polishing, and the over-light ones can be improved with the needle.
The designs made in this manner possess more delicacy as well as more strength than the ordinary crayon designs, and there remains to be desired only that they might have the advantage of the latter of being worked black on white, as it is so much easier for the artist to judge his work on the stone.
Of trials made in this direction, the two following ones met my views the best.
One way is to grind the stone rough, pour diluted aquafortis and nutgall over it, clean it with water and dry it. Then the design is drawn on it with a black chalk made of oil of vitriol, tartar, and lampblack. The further treatment is the same as that in the case of designs done with preparing-ink.
I have not been able to give enough time to this process to invent a preparing-crayon that shall be very hard without losing its preparing-property. However, the compound mentioned will produce a crayon with which one can work well after a few days. It has the advantage that it may be rubbed on a shading-stump made of rolled paper, which will prove excellent for working the finest shadings into the plate.
The other way is as follows: A colorless chemical ink is made of one part wax, two parts tallow, and one part soap. This I dissolved in water and with it I coated the stone, which had been ground rough and prepared with phosphoric acid, nutgall, and gum, and then washed with water. The coating was applied very lightly, but enough so that it could bear the succeeding etching.
As soon as it was dry, I drew the design on it with a black crayon made of tartar, gum, a little sugar, and a good amount of lampblack, or I used the ordinary black Paris crayon or a fine English lead pencil. Then the design was etched, after which alum water was poured over it, and it was set aside to dry.
As soon as it was absolutely dry, I coated it with fatty color, and then cleaned the stone with oil of turpentine and gum solution. If I wanted an exceedingly smooth surface, I ground the stone gently; but then the design had to be etched deeply.
The good results of these two experiments led me to the following process: By following my instructions exactly the worker can produce striking imitations of wash as well as crayon drawings, and at the same time unite the greatest possible ease of drawing as well as certainty of good impressions, so that this process really deserves to be called one of the very best of all printing-methods.
The outlines of the drawing must be drawn on the finest and thinnest paper that can be obtained. Then a very finely polished stone is prepared with aquafortis and gum, or, better still, with phosphoric acid, nutgall, and gum, cleansed with water and dried. Then it is coated very thinly with tallow, which is patted with a very clean leather ball or with the hand, so that it shall be very uniformly laid over the stone. Everything depends on the thinness and uniformity of this tallow coating. Then the stone must be smoked with a wax torch or a tallow candle. The durability of the ground depends on this smoking, as without it a very thin coating of tallow would be penetrated by the acid.
Now the stone is ready for the design. It must not be touched by so much as a finger. The designed paper is pasted to the stone at the ends, without pulling, as the least motion would injure the stone's surface. The arrangement of elevated supports for the hand (previously described) is needed for the succeeding work. The drawing is then done on the paper with Paris chalk, delicate Spanish chalk, an English lead pencil, or with a small piece of lead. All that is drawn on the paper will impress itself on the stone underneath and remove the ground at those places, thus opening the surface for etching.
When the drawing is finished, it is etched and covered as with the etched process, and afterward is printed as in that process.
When sufficient practice has made one a master of this style, it will be amazing what great perfection, what miniature-like delicacy, and also what strength can be obtained by proper etching.
Besides, this latter process is applicable in combination with the etched process.
This method is very useful for filling-out etched or engraved designs, also for correcting and completing the various aquatint processes.
Dip a little brush into lemon juice mixed with a little lampblack and draw the design on the finely polished and prepared stone. The acid willeat little holes into it, which will take color if the lemon juice is washed away as soon as it has completed its etching, and the etched part has been dried and rubbed-in with fat color. To produce darker shadings it can be laid on the same place twice, and for lighter shadings the acid either is washed away sooner or diluted with water.
I do not doubt that a skillful chemist could invent an etching ink which would be even more perfect, and then a drawing could be washed on the stone as easily as on paper, which would mean immense advance for the art.
Stone-printing has the unique property, owned by no other process, that it is possible to print relief and intaglio simultaneously. This property makes possible so many combinations of the two processes that a book might be filled with their description. I assume, however, that the reader will have understood the entire science of the new art from what I have said, and that his own reflection will tell him what methods to use or to combine for each of his purposes. I limit myself, therefore, to a few leading methods, thus giving some fundamental idea of the manipulations.
This can be utilized in two ways:—
When the pen drawing is finished and etched, the stone may be coated with red gum covering and the needle used to draw-in the finest lines. The printing is the same as with pen work. The second way is to make the engraved or etched part of the design first, and after the stone has been rubbed-in with acid-proof ink, cleansed and dried, to draw-in the rest with the pen and chemical ink. As soon as the design is properly dried, it is etched a little and prepared, and otherwise handled like an ordinary pen drawing.
Both ways carry the advantage that the pen can be used for those parts best done with the pen, and the engraving-tool for those parts best done with it. The latter is especially excellent for very fine and elegant script, such as title-pages, the finest strokes being made first with the needle and the broader ones with the pen.
This has been described thoroughly in our chapter on etched work.
As already shown, intaglio and relief can be printed on one stone. Therefore it is evident that the two methods can be utilized still better for several plates, for instance, printing on an etched design with one or more plates that are tinted in relief, or by printing over a crayon or pen design in relief a tone plate in aquatint in intaglio.
How to do this has been explained in the descriptions of relief and intaglio methods.
This is, so to speak, the test of a good lithographer, as it is the most difficult of all methods, and demands exact knowledge of all manipulations. I will try to explain it with a few examples.
Prepare a finely ground plate with phosphoric acid and gum, wash very well with water, and let it dry. Now transfer to it a design made with soft ink or crayon, or a fresh copper-plate impression. Let the stone rest for a few hours, that the fatty colors may take hold well. Coat it with clean gumwater, and with a rag dipped into acid-proof ink try to rub about as much color on the design as appears to be required to make it withstand some etching. This etching is done with pure aquafortis which in addition has a little alum mixed with it. Etch only enough to eat away the uppermost parts of the prepared surface that have not been permeated with fat. Pour clean water over the whole stone and coat it with strong soap-water that is permitted to dry on it. Finally, clean away the soap with oil of turpentine. Ink-in with acid-proof color which will color the whole stone. Now as soon as it is wiped gently with a rag dipped in gum solution and weak phosphoric acid, the whole design will appear in white as if it had been made with preparing-ink. If the stone is inked now with acid-proof ink and treated exactly as instructed in the article on the use of preparing-ink, the design that was in relief originally will be found in intaglio.
This process is capable of great perfection and can produce true masterpieces especially if the stone is treated finally with the engraving tool.
Etch and prepare the clean stone with phosphoric acid and gum. Then put on the design with ink or crayon, and perform the succeeding etching and other manipulations exactly as in the preceding case.
In the two examples given, the plate is etched with phosphoric acid before transfers or designs are made on it. As the weak etching with aquafortis and alum does not penetrate the places where there is fat, these retain their phosphorus-preparation, and thus are not so readily destroyed by the succeeding application of soap, whereas the etched parts immediately drink in the fat as soon as the soap touches them.
In stones designed in the ordinary way, where the design does not lie on the prepared surface, but has really penetrated well into the stone, the transforming is somewhat more difficult, but can always be done after practice by using the following means:—
Wash the stone with water and then coat chemical ink or strong soap-water over it and let it dry. Then clean the stone with oil of turpentine and ink-in well with acid-proof color. Dip a linen rag into gum water and phosphoric acid and endeavor to wipe away the color from the relief design. After wiping to and fro quickly a few times, try with the finger if the design will not whiten, or if the wiping with the acid must be continued. Care must be taken not to injure the ground through too much pressure. When the design gets pretty white, ink the stone with firm acid-proof ink, and then treat as in the preceding cases.
In this way designs in relief that have not turned out as desired can be changed into intaglio, and then, by the use of successive coatings and etchings, as described before, improved by making gradations of tones. But it requires great skill, lacking which one may destroy his plates utterly.
Many kinds of scripts and designs are easier to engrave with a needle than to do in relief with a pen; or one may have workmen who can use the engraving tool better than the pen, as the use of the latter requires more industry and skill than the use of the etching- or engraving-needle.
If one wishes to transform such a design into one in relief, because then it can be printed more quickly and easily and also will give more impressions, the following method will prove useful:—
Ink the stone with good acid-proof ink, and after a few hours etch it like a pen design till it is apparent that the design is showing up. Let it rest again a few hours after etching and become quite dry. Then coat with gum. Otherwise treat it for printing like an ordinary pen design.
Now I believe that I have described faithfully and as clearly as I can all the lithographic methods to which unceasing research and endless experimentation have led me. In the following Appendix I merely make a few useful remarks, which do not pertain exclusively to lithography, yet are intimately connected with it and surely will not be unwelcome to art lovers.
Fig. 1.Figs. 2 and 3Fig. 4
Fig. 1.
Figs. 2 and 3
Fig. 4
When a plate, whether intaglio or relief, has been inked-in with oil color, it may be coated with one water color, or it may be illuminated with several, and then printed-off in one impression. Two parts of gum and one part of sugar are used for this. They can be dissolved with any water color. Care need be taken merely that the colors are well dried before the impression is made.
If, however, it is desired that the colors have shades so that the impressions may resemble English or French colored copper-plate prints, the process is as follows:—
Etch all shades of the color pretty deeply in any of the stippled or aquatint styles. After this, coat the stone with gum solution, that it shall take no color in these depressions. Clean off the chemical ink or the ground with oil of turpentine, and prepare the whole plate if it has not been prepared already on its surface. Then coat it with red gum surface, and into this inscribe all those lines that are to remain black. Then the color is rubbed-in and the stone cleansed so that it will be white everywhere except in the engraved parts. When it is inked-in now, it can take color there only, and the other depressions (namely the various shades of the color) will remain white because they have been prepared. Now it is necessary only to coat each part with the desired water color and it will be denser, and therefore darker, wherever there are more and greater depressions.
When a pen drawing is so constituted that the various lines are close together and there is no white space on it that is greater than at most one half inch in diameter, it will permit printing in a purely mechanical waywithout being prepared. It need merely be etched into all the relief possible without under-eating the lines. All that is needed then is a color-board or a so-called dauber, made as follows:—
A thin board of soft wood, about eight inches long and six inches wide, is planed down till it is not more than one line in thickness. Glue on it a piece of fine cloth or felt almost as large as it. Over this glue another board, of the same area as the first, but one quarter inch thick. It must be very well-dried wood, and must be made very true with the plane, or better still, by rubbing on a perfectly level stone with sand. This latter board is provided with a handle; and when all is dry this dauber is ground off true again with fine sand and oil on a stone.
Lay the printing-color on this utensil very gently and uniformly with a leather ball. Tap and pat the stone, which has first been cleaned with oil of turpentine over its whole surface, very carefully with the appliance, holding it as horizontal as possible and taking great pains to distribute the color evenly.
As compared with chemical printing, this process in itself has no advantages, but can be united with it and thus used to print three colors from one plate. This is shown by the following
Suppose that a design shall be colored black, blue, and red, and that all these colors shall be put simultaneously on one plate. Take a stone made ready for pen work, and prepare it first of all with phosphoric acid, nutgall, and gum, then wash it with water, and let it dry. Now draw-in all that is to be red with chemical ink, that must, however, contain only just enough soap to permit its solution. When this drawing is dry, etch it into pretty high relief, the higher the better. After this prepare the stone with gum, wash it, and let it dry again. Then coat it with etching-ground that has been dissolved in oil of turpentine, and draw-in all that is to be black, between and over the high etched parts. Then etch this design pretty powerfully into intaglio, after which wash with water, rinse with alum solution, and dry. When the plate is thoroughly dry, rub-in printing-color,and clean with a woolen rag dipped into gum solution and oil of turpentine. Then it will become white everywhere except in the deep lines where it will have taken color. After cleansing again with water and drying, draw-in all parts that are to be blue, using a chemical ink that contains a great deal of soap. Let this dry well, and cleanse the plate with gum and oil of turpentine again. Then it is ready for inking-in.
To lay on the color, proceed as follows:—
First the black is rubbed-in, as prescribed in the article on the intaglio style. In the very deep parts the stone will get very black. In the parts last drawn, that are level with the surface, it will be only gray, if the color permits ready wiping, which can be facilitated by the use of gum and a woolen rag. Then the tone remaining on the level parts drawn with the chemical ink will be so pale that it will not affect the blue color. Now wipe a rag dipped in blue color gently to and fro till everything that is to be blue has taken the color well. Then take the dauber which has been filled with red color, and pat the stone, which should be dry by that time. Then the parts of the design in high relief will take the red color, and thus an impression can be made with the three colors at once. Each inking-in must be done the same way.
Etched copper plates have been used for some considerable time for cotton-printing, and as the ordinary oil colors were not suitable for this, while the suitable colors were too fluid, so that they were always wiped out of the engravings, another method was devised. The plate was covered with color and then a kind of straight edge was scraped across it, which removed all color from the surface, leaving it only in the depressions.
This same sort of wiping is applicable to stone, and it is necessary merely to see that the stone is very even and highly polished. The color must be one that permits itself to be wiped off clean, and the wiper must be very uniform and sharp.
Starch-paste or gum with some caustic material is easily scraped off.
This process is also useful for printing papers such as cotton papers, tapestry, etc. Almost all intaglio designs permit good printing in this way, if a handsome color is used.
Fresh cheese, or drops of congealed milk, mixed with soap, potash, linseed oil varnish, and the desired tint, make an excellent composition, with which all intaglio designs, even aquatints, can be printed handsomely if the plate is very smooth.
If the design is made well, the various colors can be laid on quite roughly, care being taken merely that each color shall be laid only where it is desired. Then the stone should be permitted to dry, after which all the surplus colors can be scraped away with one manipulation, without danger that one will mix with the other in the design.
Colored impressions resembling oil paintings can be made by printing with colors and several plates on paper grounded with oil color. But perfect oil paintings are produced only as follows:—
Make a considerable quantity of special paper by coating unsized paper thinly with starch-paste or glue. On this make the separate impressions from each color plate. If the painting itself is to be produced from these separate parts, take a canvas that has been prepared for oil painting and lay on it a wetted impression of one of the colors, let us say, red. Print this off under light tension of the press, and when the paper is pulled away, it will be seen that the color has been transferred to the canvas. Then a wet impression of another color is laid carefully in place so that it will register exactly, and the process is repeated, till all the colors have been transferred to the canvas.
The transferring can be done with the hand or with any other method, as no great power is needed, since the color transfers itself readily.
This is the name already generally adopted for a substitute invented by me for the Solenhofen stones.
I had been trying for a long time to invent some stone-like mixture that would be equally suitable for printing. The ordinary parchment of the writing-tablets would do if its surface were not soluble in water. I made considerable progress with a composition of lime and freshly congealed milk after the mixture had aged enough so that the lime could sate itself with oxygen. Then I made a composition of chalk, gypsum, and glue, which I dipped into a solution of nutgall and alum, and I was able to use this for coarser work, at least, if not too many impressions were required.
I did not get a wholly satisfactory idea, however, until I observed that fat spots that were caused on a stone by oil, and also designs that had been transferred to the stone with mere oil color, refused to take color after a few weeks if they were prepared in only the slightest degree.
I reasoned from this that oil suffered a change from exposure to air, and by combining itself presumably with oxygen acquired a more earthy character. This deduction may be correct or not; but it led me to experiment with oil as a binder for various earthy substances, because I reasoned that such a composition would be insoluble in water. The only question, then, would be if despite the intermixed oil it would permit itself to be prepared, that is, if it could be made resistant to other fats.
The result justified my hopes so thoroughly that I am convinced now that with various compositions of clay, chalk, linseed oil, and metallic oxides a stone-like mass can be made that is excellent for coating paper, linen, wood, metal, etc., and thus for making plates that not only replace the stone for printing, but in many cases are far superior to it.
I shall give the world a book soon about these fortunate attempts of mine, and thus perhaps give expert chemists an opportunity to perfect my invention still more.
All metals have great inclination for fats; but if they are quite clean, being ground with pumice, for instance, or rubbed-down with chalk, they can be prepared like a stone, that is, they acquire the property of resisting oil color, thus becoming available for chemical printing.
Iron and zinc can be prepared like the stone with aquafortis and gum.
To prepare zinc and lead, aquafortis with nutgall and gum will serve, but a slight admixture of blue vitriol will make still a better preparation, and this in a degree that improves according to the amount of copper that the surface acquires from the coating. The most durable preparation for lead and zinc is a mixture of aquafortis, gum, and nitrate of copper.
Brass and copper are best prepared with aquafortis, gum, and nitrate of lime, all mixed in proper proportions.
Lime and gum are a good preparation for all metals; also potash with salt and gum.
This alkaline preparation, however, is applicable only for the intaglio style. For the relief style, the acids are better.
Recently I have applied chemical printing from metal plates to a new form of copying-machines, with which everything written or drawn with chemical ink or crayon on paper can be transferred in a few moments and manifolded several hundred times. His Royal Majesty of Bavaria has had the supreme condescension to grant me a six years' patent on this invention.
Until now I have not been able to give this matter the necessary attention because the work of publishing this book hindered me; but now I shall make such a stock of these simple, convenient, and so widely useful hand-presses that it will be worth while to open a subscription, which would enable me to sell them for a low price. This would please me best, as my highest reward would be the general use of my inventions, to fulfill which desire I have taken the utmost pains in this work.
In the last parts of the book I have gone less into details, merely becauseI assume that those who have mastered the first parts of this work will not need many words to understand the rest.
If the demand for this perhaps prematurely announced book had not become so vehement lately that I could not possibly delay its publication any longer, I should have tried to produce sample illustrations that combine inner art value with good printing. As it is, I postpone this for a supplementary volume soon to appear, in which I shall occupy myself mainly with processes and methods not yet generally known, representing each by means of a true work of art. With which I now end my text-book, with the hearty wish that it will find many friends and create many good lithographers. This may God grant!
The Riverside PressPRINTED BY H. O. HOUGHTON & CO.CAMBRIDGE, MASS.U.S.A.
Transcriber's Notes:Punctuation and spelling standardized.Inconsistent hyphenation retained.This book had no overall Table of Contents; the one before the start of the book was created by the transcriber.
Transcriber's Notes:
Punctuation and spelling standardized.
Inconsistent hyphenation retained.
This book had no overall Table of Contents; the one before the start of the book was created by the transcriber.