Secco is an Italian term meaning dry. Among the various techniques used for mural painting, a secco is defined as a technique executed on an already dry intonaco. In this case, differing from fresco, organic binders (animal or vegetable glue) or lime water may be added, to favour the adhesion of colours to the surface. Also in fresco, one notes the recurrence of a secco painting in the execution of details and in retouching.