Heralded as the greatest artist of the triumvirate of modern illustrators that included Greenaway and Crane, Randolph Caldecott is highly praised for introducing techniques of animation into picture book art and for his humorous, satiric extensions of the text in his illustrations. Caldecott's fame centers on 16 books, often referred to as the "Toy Books," reprinted by Edmund Evans in his innovative printing techniques, featuring mainly traditional nursery rhymes and songs, and published in pairs. They include: The House That Jack Built (1865), The Diverting History of John Gilpin (written by William Cowper) (1878), Elegy on the Death of a Mad Dog (written by Oliver Goldsmith) (1979), Babes… in the Wood (1879), Sing a Song of Sixpence (1880), The Three Jovial Huntsmen (1880), The Farmer's Boy (1881), The Queen of Hearts (1881), The Milkmaid (1882), Hey Diddle Diddle with Baby Bunting (1882), A Frog He Would a-Wooing Go (1883), and The Fox Jumps over the Parson's Gate (1884). Caldecott generally drew his illustrations in sepia applied with a brush rather than a pen; he included an average of three uncolored illustrations for each colored one. He has received praise for his fluid style, which created a sense of movement across a page and from one page to another; he is also lauded for his insight into human nature and instinctive grasp of what appeals to children. Each year the American Library Association awards a highly coveted medal in his name to the best illustrated book by an American author.