A polished copper plate is grained by dusting resin or asphalt powder on its surface, and afterwards fixing it by the application of heat. A _tissue_ negative print is made, squeezed on to the grained plate, and developed in the usual way. The plate is etched through the tissue. The action of the etching mordant--perchloride of iron--being in exact proportion to the light and shade of the developed print. The printing is a necessarily slow, and therefore costly, item. This limitation to their production, however, enhances the value of photogravure prints. =Ink Photo.=--What is known as the ink photo process of reproduction is interesting chiefly on account of the remarkable fidelity with which engravings of the finest and most intricate texture can be reproduced by its agency. It is essentially a photo-mechanical process, but differs from others of a similar character, inasmuch as the vigour and expressive power of the original is to a considerable extent preserved. Colour values also, as far as they can be expressed by the engraver's art (see p. 11), are reproduced by ink photo methods with surprising accuracy, and the intensity of impression, that peculiar feature of prints from engraved plates, is almost invariably well sustained. A careful criticism of the appended illustration and frontispiece done, this process will reveal many other interesting points of practical value. CHAPTER VIII _APPRECIATIVE CRITICISM_--AN EDUCATIVE PRINCIPLE--AN ANALYSIS--REALISM IN ART--A RETROSPECT "Yet when we have said all our fine things about the arts, we must end in a frank confession that the arts, as we know them, are but initial. He has conceived meanly of the resources of man who believes that the best age of production is past." =Appreciative Criticism.=--The art of engraving, and particularly wood engraving, has fully justified its existence, and the eminently popular position which it has long held amongst the fine arts of the world. Through the medium of the pictorial press it has diffused a knowledge of the noblest principles of art, and has ever exerted a refining influence even over inartistic minds. For this reason the lack of knowledge concerning some of the essential qualities of engraving as a pictorial art is somewhat remarkable. Even more so when it is considered that never before in the history of the world has such a wealth of illustrative art been produced and brought well within the reach of its humblest patrons.