Had my skill in writing and drawing on stone been greater at that time, Herr Steiner would have given me opportunity enough and manifold. He permitted me to do a small book, Rules for Girls, in German script, which, on the whole, turned out of only average quality, as I had not practiced this style sufficiently.
Then he wanted me to draw Biblical pictures on stone or to let others draw them. At that time he was having Herr Schön in Augsburg etch the Seven Holy Sacraments after Poussin. As the etching was expensive, the impressions could not be sold for less than four kreuzer each. Herr Steiner wished to circulate these pictures so generally that they could serve as gifts from the country preachers to their little Christian pupils. He wished, also, to ornament various school-books with pictures of this kind, and thus, gradually, to replace the miserably drawn species of saints that generally fill the prayer-books of the pious households.
Only the utmost cheapness could make this possible, and this naturally suggested the stone process to him. Even if the pictures were not so fine as those etched on copper, they would serve amply if they were correctly drawn, noble in design, and handsomely printed. It was necessary either to draw myself and practice faithfully, or to train a skilled artist to draw with fatty ink on stone. We preferred the latter method and trained several young men, who produced various works, sometimes good, sometimes inferior.
Through all this I ran more and more danger of losing my secret. Indeed, it was lost already except perhaps so far as concerned the exact composition of the ink. But I hoped still to obtain the privilege for Bavaria, toward which end the Schulrath promised me his best aid, and so I let the matter proceed, and trained the men. But among all these young men there was not one who did not desire a substantial reward for his very first attempts, and when they found that they were expected first to learn, they stayed away, one by one. Herr Steiner was hurt. I, however, was indifferent, for I was just beginning to plan to use a new and important discovery in such a manner that my stone-printing would be greatly improved and we could hope to carry out our idea of illustrations without the aid of artists.
I had been assigned to write a prayer-book on stone for the Schul-fond. It was mostly in a style of writing in which I was least expert. When I wrote music notes, our method, proved best by experience, had been to write the entire sheet in reverse on the stone with lead pencil to serve as pattern. This was mostly Herr Gleissner's work, and being a musician he had achieved great perfection. For me this preparatory work was far less agreeable than the final execution with the stone-ink. Therefore, as ever in my life, when a difficulty or a burden was before me, I studied for some way to make it easier for me. Previously I had found that if one wrote on paper with good English lead pencils, then moistened the paper, laid it on a polished stone and passed it through a powerful press, a good impression was the result. I had used the method on various occasions. I wished that I possessed an ink that could be used the same way. Trials showed that fine red chalk needed merely to be rubbed down gently in a solution of gum, and that even the ordinary writing-ink of nut gall and vitriol of iron would serve when mixed with a little sugar. But this did not satisfy my ambition, which always demanded the best and most perfect. The gum in one and the vitriol in the other did not agree well with the stone-ink. In addition, the impression often squashed. Therefore I tried a mixture in water of linseed oil, soap, and lampblack which met my demands better. I had a music-writer write notes correctly on note-paper with this ink, printed it on the stone, and thus had an accurate pattern, which was at the same time reversed, as was necessary.
I now planned to do this with the book. But why could I not invent an ink that would serve on the stone without making it necessary to trace over it with the stone-ink? Why not make an ink that would leave the paper under pressure and transfer itself to the stone entirely? Could one give the paper itself some property so that it would let go of the ink under given conditions? So reflected I, and it seemed to me not impossible. At once I began to experiment. I had observed that the stone-ink at once began to congeal and stiffen when it came into contact with ordinary writing-ink, because of the action of the vitriol of iron, which devoured the alkali that the stone-ink needed to keep it in solution. Therefore I wrote with ordinary ink, into which I put still more vitriol of iron. After it was dry, I dipped the sheet into a weak solution in water of my stone-ink. After a few seconds I withdrew it and washed it very gently in rainwater. I found that the ink had fastened itself on the written places, and pretty thickly, too. I allowed the paper to dry slightly and transferred the writing to the stone. The impression was fair, but not sufficiently complete. I tried it repeatedly but could obtain no transfers that were sharp and uniform enough to represent a handsome script. So I tried another way. I painted the paper with gum solution in which vitriol of iron was dissolved. After it dried I wrote on it with my ordinary stone-ink and dried it again. Then I dampened the paper and let it lie a while to soften, after which I transferred it to the stone, which had been treated with strong oil varnish diluted in oil of turpentine, laid on so lightly that it was only like the blurring from a breath.
These attempts were far more successful, but it was impossible to write as delicately on this paper as I desired. Therefore I made new experiments. I changed the mixture of my ink. I tried to make it more adhesive with mixtures of resin, oil varnish, gum elastic, turpentine, mastic, and similar substances. In short, I do not exaggerate when I declare that this matter cost me several thousands of experiments. I was rewarded sufficiently by succeeding. And at the same time through these investigations I discovered the chemical printing on stone of to-day.
As the transfer from paper to stone depended mainly on the greater or lesser powers of adhesion between one material and another, it was natural that in my many experiments with such various ingredients I should observe that a mucous fluid, as, for instance, the gum solution, resisted the adhesion of the greasy ink. Nearer still to the new invention did the following experiment bring me: I noticed that if there happened to be a few drops of oil in the water into which I dipped paper inscribed with my greasy stone-ink, the oil would distribute itself evenly over all parts of the writing, whereas the rest of the paper would take no oil, and especially so if it had been treated with gum solution or very thin starch paste. This fact led me to investigate the behavior of paper printed with common printing-ink.
A sheet of an old book was drawn through thin gum solution, then laid on a stone and touched carefully everywhere with a sponge that had been dipped into a thin oil color. The printed letters took the color well everywhere and the paper itself remained white. Now I laid another clean white sheet on this, put both through the press, and obtained a very good transfer, in reverse, of course. In this manner, if I used great care, I found I could make fifty and more transfers from the same sheet. If I allowed such a transfer to dry thoroughly and then treated it like the original sheet, why should it not produce transfers that are like the original, not reversed? So thought I, and the result showed that I had not been wrong! Only for the first transfer I needed to use a somewhat stiffer color that had been dried more with litharge of silver, and then to let the transfer dry for at least four or six days.
So I came to find that I could print without a stone, from the paper alone; and this process, depending solely on chemical action, was totally, fundamentally different from all other processes of printing.