AN instinctive love of colour often found expression in the art of wood engraving, as it did in all arts. The car liest examples of European wood engraving, dating from the beginning of the fifteenth century, were pictures of sacred subjects cut in bold outlines on blocks of wood and impressed on paper by means of rubbing. Their popular appeal, apart from the subject, rested, no doubt, in their bright colours, applied by hand with the aid of brushes and stencils. This method of colouring continued in use long after the invention of printing in the middle of the fifteenth century, and although even then efforts were made to print colours from wood blocks, they sel dom remained unassisted by the colourist's hand, so that colour printing proper may be said to begin with the invention of engraving and printing in a manner called chiaroscuro or clair-obscur.