18c reading list
Gombrich's Art and Illusion
Walter Friedlaender's From David to Delacroix/ "Napoleon as roi thaumaturge"
Frederic Antal's Classicism and Romanticism
Edgar Wind's David Hume and the Heroic Portrait / "Sources of David's Horaces" and "Revolution of History Painting"
Friedlaender's student Robert Rosenblum's Transformations in Eighteenth-Century Art (1967)
David Solkin's Painting for Money (1986)
Tom Crow's Painters and Public Life in Eighteen-Century Paris (1984, easy to find in some article forms including one on David from 1979; his second book Emulation, 1999, about the French Revolution is less loved but also very interesting).
Mary Sheriff's Fragonard (1990) and Vigee-Lebrun (1996) is close behind as a major feminist work, but I'd rather recommend her last 2 books, Moved by Love (2004) and Cultural Contact and the Making of European Art since the Age of Exploration (2010).
Ewa Lajer-Burcharth's books, The Painter's Touch: Boucher, Chardin, Fragonard (2017, very good on earlier 18th C. French), and Necklines (1999)
David Bindman's Ape to Apollo (2001)
TJ Clark, "Painting in the Year Two" (1994)