 Darly's most important publication— his chief claim to being credited as an architect— was "The Ornamental Architect or Young Artist's Instructor...Consisting of the Five Orders drawn with their Embellishments" (1770–1771), a title which was changed in the edition of 1773 to "A Compleat Body of Architecture, embellished with a great Variety of Ornaments".He also issued "Sixty Vases by English, French and Italian Masters" (1767).In addition to his immense mass of other productions Darly executed many book plates, illustrated various books and cabinet-makers' catalogues, and gave lessons in etching.