Signs of art are immaterial, while giving no indication as to whether this is a good or bad thing.
No one has time to read the legend. Silly artworks resonate with internal logics of their own.
Most art symbols are worn-out clichés that have outlived their usefulness.
Artworks break with fate.
The art sign may reveal a view of an hidden picture that reads as a separate drawing. Live forever or die in the attempt. Sgraffito, both as natural phenomenon and as cultural metaphor, is the subject of a painting.