OCR Text |
Show PHOTOGRAPHING IN PRINTING INK.. Some time in lS'.'-S a Copenhagen photographer, by the name of Key, invented in-vented a process for printing photographs photo-graphs w;th ordinary printing ink, but. owing to the difficulty usually experienced experi-enced in bringing such improvements into general uc, no practical results were obtained I'rom the invention, we believe, until the outbreak of the recent re-cent continental war, when it was used in reproducing exact copies in miniature minia-ture of the London papers, etc., lor transmission by balloon or pigeon to Paris. The rieht to use the invention in the the United States was recently purchased and the process introduced ;uto this country by some ea.-tern photographers, pho-tographers, who have made several important improvements on the original origin-al invention, with a view to adapting it to the uses of book publishers aud others, in lieu of the less perfect aud more costlv systems of engraving and lithographing. By this system pictures both portraits and landscapes are produced with all the fidelity aud vigor of photography, and with the absolute permanency of printing ink. The process pro-cess introduced is of the simplest and most reliable nature. Under ordinary photographic negatives, prepared plates of glass, zinc and stone, are exposed ex-posed to the action of light, and from these plates thousauds of pictures arc printed with all the facility of the ordinary ordi-nary lithograph upon a press with ink. The effect of the light upon the sensitized sensi-tized plate is to transform it into a veritable lithographic plate tlie parts exposed to the action of light having an affinity for fatty or printer's ink, and the portion protected from light rejecting the ink and absorbing water. So, first a wet roller is passed over a plate that is ready for the press, followed fol-lowed by an ink roller, and the paper then placed on the press and run through the rollers at the rate of about sixty or seventy an hour. |