secco

secco (It.: ‘dry’). Term applied to a technique of mural painting in which the colours are applied to dry plaster, rather than wet plaster as in fresco. The colours were either tempera or pigments ground in lime water; if lime water was used, the plaster had to be damped before painting, a method described by Theophilus and popular in northern Europe and in Spain. In Italian Renaissance art the finishing touches to a true fresco would often be painted a secco, as it is easier to add details in this way; because the secco technique is much less permanent, such passages have a tendency to flake off with time. Thus in Giotto's Betrayal in the Arena Chapel, Padua, the details of many of the soldiers' weapons are now missing.