Produced by Lesley Halamek, Chris Curnow and the Online Distributed Proofreading Team at https://www.pgdp.net (This file was produced from images generously made available by The Internet Archive) THE ESSENTIALS OF ILLUSTRATION A PRACTICAL GUIDE TO THE REPRODUCTION OF DRAWINGS & PHOTOGRAPHS FOR THE USE OF SCIENTISTS & OTHERS By T. G. HILL Reader in Vegetable Physiology in the University of London, University College LONDON WILLIAM WESLEY & SON 28 Essex Street, Strand 1915 PRINTED BY THE WESTMINSTER PRESS, LONDON, W. CONTENTS PAGE INTAGLIO PRINTING 1 Intaglio plates 2 Line engraving 2 Etching 5 Soft-ground etching 6 Mezzotint 7 Photogravure 8 PLANE SURFACE PRINTING 15 Lithography 15 Chromolithography 20 Photolithographic processes 23 Collotype 23 The preparation of illustrated pages 26 RELIEF PRINTING 33 Woodcuts and engravings 33 The Half-tone process 37 The Half-tone three-colour process 46 Photomechanical line blocks 49 The drawing of microscopic details 67 The drawing of diagrams and apparatus 72 The drawing of maps 76 The drawing of graphs or curves 79 The swelled gelatine process 84 The Relative Cost of blocks and plates by various processes 89 LITERATURE 95 ILLUSTRATIONS 1. PLATES PLATE 1 An original lithograph by Mr. Harry Becker. 2 Chromolithograph. Messrs. Gerrards, Ltd. 3-5 Collotype. Messrs. Andre, Sleigh & Anglo, Ltd. 6 Half tone. Swan Electric Engraving Co., Ltd. 7 Half tone. \ | 8 Photogravure. | | 9 Collotype. | Messrs. Andre, Sleigh & > Anglo, Ltd. 10 Half tone. | | 11 Half tone. | | 12 Half tone three colour. / 2. TEXT FIGURES Tailpiece, p. 11. Electrotype from the original wood engraving by Bewick. Tailpiece, p. 30. Line block. Messrs. Bourne & Co. Fig. 1. Wood engraving. Messrs. Edmund Evans, Ltd.