Typo: A Monthly Newspaper and Literary Review, Volume 4
Inventions, Processes, and Wrinkles
Inventions, Processes, and Wrinkles.
Automatic Paper-Cutter and Printer.—
The system now so much in favor of using wrapper-paper from the roll, has given rise to an invention by a genius in St. Louis. He combines a printing attachment to the roll, which is operated at each revolution. A separate attachment enables bags and flat papers also to be printed.
The occasional practice of casting sloping founts on oblique bodies is not by any means new; but we believe that the useful improvement now made use of by Gustave Mayeur, of Paris, is. In his « Algerian Ornate, » the two larger sizes are cast in the usual style for oblique type, with three-sided quads at the end to make the lines lock up true. In the smallest size there is a considerable advance on this practice. Every letter is cast with a projection on one side and a corresponding slot on the other. This locks the letters, and prevents the types from slipping out of line, as they infallibly do in the ordinary system. A small three-sided space, which is scarcely necessary, is provided to fill the opening in the first letter. The only defect we see in these obliquely-east letters is, that it is impossible to make a full line with them. In the larger styles, the slope above the letter keeps it at least an em from the end of the measure.
Cold-melting Apparatus for Lithographers.—
The Senefelder export house (Krebs), Frankfort-on-the-Main, has introduced an apparatus patented in Germany, by means of which powdered resin, which is dusted over litho-stones or zinc-plates before etching, is melted without heat. It is possible with this apparatus to cover any engraving, crayon, or pen-drawing on stone or zinc with the necessary coat of resin, and to etch it within a few minutes. The solution of the resin is effected by the vapor of ether, and the advantages gained by using the apparatus are principally due to a movable car and adjustable ether-plates, all danger of spoiling the work by touching the plate or stone being thereby avoided. A further advantage lies in the facility with which the resin may be melted on a part of the surface only, by passing the car rapidly over other parts, thus exempting them from the effects of the ether-vapor. The work is never, as in other methods, removed from view.—American Lithographer and Printer. [There seems some confusion of terms here, « melting » being used in place of « dissolving. » The practical effect, however, appears to be the same.]
Under this name has been introduced a system of producing newspaper illustrations, which appears to be the simplest yet in use. A black glass plate or a tin plate coated with black varnish, such as is used by sign painters, is covered with plaster-of-paris (which must be of the best quality and reduced to a fine powder) to about the thickness of a four-sheet card. To the plaster is added some alumn and some sulphate of barium, and a small proportion of glycerine or of gelatine solution to prevent the coating from becoming too brittle. The mixture, in the consistency of a pulp, is applied with a soft camel-hair brush, and allowed to dry. The artist, with a lithographic needle, may then engrave any design or sketch with the greatest ease; the drawing, as the plate is laid bare, appearing in black on a white ground. Errors are easily remedied by filling-in with the preparation. With ordinary roller-composition (to which some solution of bichromate of ammonia has been added) a stereo is now taken from the mould, and when properly mounted it will be found to work in a typographic press, and to be as durable as an electrotype. The bichromate should be dissolved in the proportion of 1 oz. to 1 pint distilled water; to this add J-oz. alcohol. The greater the proportion of bichromate, the harder the plate; but it should have some elasticity. Too great a proportion of the bichromate will make it leathery.