In buon fresco, which literally means good fresh, the water color and lime (the mineral not the fruit) are painted directly on damp plaster that has just been applied. Fresco secco (Italian for dry fresh) is a little less permanent and the paint sometimes can flake off the walls.resco is a term that literally means fresh.. There are two kinds, buon fresco and fresco secco. This painting painting is made by coating a wall with plaster and while the wall is still damp, ground up pigments are mixed with water and lime and painted on the wall.