Alla prima is a style of painting where, instead of building colors up with layers or glazing over an underpainting, the painting is completed while the paint is still wet. Strictly defined, an alla prima painting would be started and finished in one painting session, but the term is also more loosely applied to any painting done in a direct, expressive style, with minimal preparation.
Alla prima comes from Italian, literally meaning “at once”. The French term is premier coup.