Half-tones are occasionally printed on a kind of vegetable parchment, a paper which should be more extensively used since it will sometimes, but not always, give as good a reproduction as art paper, and the final result is more pleasing from the artistic point of view. [Illustration: G. Oliver, del.] RELIEF PRINTING [Illustration: Little maid, little maid, Whither goest thou? Down in the meadow To milk my cow. Fig. 1.--A wood engraving, by Edmund Evans, from the original drawing by Kate Greenaway. Reproduced by permission of the publishers, Fredk. Warne & Co.] RELIEF PRINTING In order that illustrations may be incorporated in the text, the blocks used must be in relief the same as the type; a mixture of intaglio and relief is impossible, for the whole surface must be level in order to be inked by the rollers, which deposit the pigment evenly, so that only one tone of colour--that of the ink--is possible. Up to quite recent times wood cuts and engravings were the only means available for text-illustrations, so that this method may next be considered.[A] [Footnote A: See Treviranus, C.L.: _Die Anwendung des Holtzschnitts zur bildlichen Darstellung von Pflanzen_. Leipzig, 1855.] WOOD CUTS AND ENGRAVINGS. The invention of illustrating by means of wood blocks followed closely on the heels of the use of moveable types for printing. The Chinese were the first, as far as is known, to use these methods of printing and illustration; in the western world the first wood blocks date from the beginning of the fifteenth century.