. The half-tone process. A practical manual of photo-engraving in half-tone on zinc, copper, and brass. Fig. 7. of good screens are sharp and clear under a magnifyingpower of 100 diameters. It was formerly the practiceto use a single line plate, and to reverse the directionof the ruling by turning the plate a quarter revolutionduring the exposure, but this method is now obsolete. Screens formed of circular dots instead of lines havealso been tried, but abandoned by all practical HALF-TONE MADE ETCHED ON COPPER WITH MAX LEVYS BY THE ENAMEL 400 LINE SCREEN. PROCESS BY THE WALKER ENGRAV
. The half-tone process. A practical manual of photo-engraving in half-tone on zinc, copper, and brass. Fig. 7. of good screens are sharp and clear under a magnifyingpower of 100 diameters. It was formerly the practiceto use a single line plate, and to reverse the directionof the ruling by turning the plate a quarter revolutionduring the exposure, but this method is now obsolete. Screens formed of circular dots instead of lines havealso been tried, but abandoned by all practical HALF-TONE MADE ETCHED ON COPPER WITH MAX LEVYS BY THE ENAMEL 400 LINE SCREEN. PROCESS BY THE WALKER ENGRAVING CO. NEW YORK. THE SCREEN. -5 Grained screens and chess-hoard screens offermore promising alternatives to the half-tone screen,but at the time of writing they have not come intocommercial use. The old plan by which the operator made his screensby copying the proof from a copper plate engravedwith parallel lines has also been quite superseded, asalso the clumsy makeshift of using wire gauze, silk net,muslin, crape, or tulle. The choice of a screen really becomes a simplematter, owing to the limited number of makers. Levy,of Philadelphia, , and Wolfe, of Dayton, Ohio,, are the oldest established ones ; but very goodscreens of a similar character were put on themarket recently by Johnson, of Leicester, and Haas,of Frankfurt-on-the-Main. The author knows of noother screen makers of importance. Levy screens have undoubtedly the highest reputa-tion, and are the most exten
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Keywords: ., bookcentury1900, bookdecade1900, bookidhalftoneproc, bookyear1904
