Randolph Caldecott
Randolph Caldecott (; 22 March 1846 – 12 February 1886) was an English artist and illustrator, born in Chester. The Caldecott Medal was named in his honour. He exercised his art chiefly in book illustrations. His abilities as an artist were promptly and generously recognised by the Royal Academy. Caldecott greatly influenced illustration of children's books during the nineteenth century. Two books illustrated by him, priced at a shilling each, were published every Christmas for eight years.
John Rocco
Rocco was a runner-up for the American Library Association Caldecott Medal, which annually recognizes the best in U.S. children's picture book illustration, when "Blackout" was named a Caldecott Honor Book in 2012.Another artist illustrated the first edition dustjacket for at least the first Camp Half-Blood novel by Rick Riordan, namely "The Lightning Thief". Before the end of the "Percy Jackson & the Olympians" subseries (2005 to 2009), all volumes were in print with stylistically matching dustjackets illustrated by Rocco. New cover illustrations from a single Rocco painting that spans all five books were introduced early in 2014.