Senefelder had just ground and polished a stone, when his mother entered the room and asked him to take a memorandum of some clothes which she was about to send away to be laundered. Having neither paper nor ink at hand, he hastily wrote the items with a pen, dipped in his acid-resisting mixture, upon the stone which had just been polished. When he afterwards started to wipe the writing from the stone, it occurred to him that it might be possible to reverse his process by etching the surface of the stone, leaving the writing or drawing in relief, which could be printed from in the same manner as from type. He was fairly successful in this, and after many disappointments and much hardship, he eventually succeeded in interesting a capitalist, with whose assistance he was enabled to establish his new relief stone process on a commercial basis.
The process, however, was at best only an imperfect one, and it seems strange that the final discovery of surface or lithographic printing should have been so long delayed, when Senefelder was in reality so near it, when he first poured the acid over the stone containing his laundry memorandum. If he had instantly washed off the acid and cleaned the surface of the stone with water, he might have proceeded to print thousands of impressions by simply keeping the surface of the stone moist while passing the ink roller or dabber over it, then drying and taking an impression, and repeating this operation indefinitely. It is not surprising, therefore, that a man of such persistence and capability as Senefelder should eventually discover the best method for drawing and printing from stone; for it is a fact that, since he perfected his invention, more than a hundred years ago, it has been hardly possible to improve on his methods, so completely did he cover the entire field of manipulation in this direction. Continuing his experiments, Senefelder finally found that the calcareous stone absorbed and held grease, and that it just as readily absorbed water, where the surface was exposed and clean; that any design drawn or transferred with a greasy crayon or ink upon a cleanly polished stone would be firmly held, after being slightly etched; and that after such a stone had been moistened, it could be inked with rollers, the ink adhering only to the greasy matter constituting the design (although it did not stand out in the relief) and that the ink rollers would not smut the stone, the ink being repelled by the water or moisture covering its surface. Upon this principle of chemical affinity, the adherence of greasy substances to each other and the mutual antipathy of grease and water, the art of lithographic printing is based.