Glazing is a painting technique in which thin transparent layers of paint are built up over a dried opaque underpainting to produce luminous depth.
Glazing is a fundamental oil-painting technique in which thin layers of transparent or semi-transparent paint, made by mixing pigment with a generous proportion of oil or medium, are applied over a dried opaque underpainting. Light passing through the upper transparent layer is partially absorbed and partially reflected back from the layer beneath, producing colours of a depth and luminosity that direct mixing on the palette cannot achieve. The technique was perfected by the Flemish painters of the 15th century — Jan van Eyck, Rogier van der Weyden, Hans Memling — whose oil panels remain extraordinary even after six hundred years. Titian and the Venetian school adapted the technique to a freer Renaissance manner. Vermeer, Rembrandt, and the Dutch Golden Age painters used glazing extensively. The 19th-century French academic painters made it a defining mark of high finish. With the rise of Impressionism, alla prima painting (wet-on-wet, completed in a single sitting) largely displaced glazing for several decades, but the technique was revived in the 20th century by hyperrealists, classical revivalists, and contemporary representational painters.