Macadam was a British illustrator active in the 1920s and 1930s. Amongst his commercial works are several dust wrapper designs for London-based publishers, most important amongst which is the design for the dust wrapper for the first edition of Agatha Christie's first straight novel Giant's Bread. Following the discovery of an archive of Macadam's work in 2016, it was possible to connect his work on Giant's Bread to other known designs.