Rectilinear forms stay put in relation to gravity, and are not likely to tip over. This stability suggests permanence, reliability and safety. In the case of the man in this family group, the lines seem to imply stability to the point of stodginess. Deep, acute curves , on the other hand, suggest confusion, turbulence, even frenzy, as in the violence of waves in a storm, the chaos of a tangled thread, or the turmoil of lines suggested by the forms of a crowd. The complicated curves used to form the mother in the family group shown above suggest a fussy, frivolous personality.
Curved lines do vary in meaning, however.
Soft, shallow curves suggest comfort, safety, familiarity, relaxation. They recall the curves of the human body, and therefore have a pleasing, sensual quality. The quality of the line is in itself a fundamental visual language, to an extent that cannot be claimed for any other single element. Its use is so universal that we are all profoundly sensitive to it. Even without an artist's training, we can extract considerable meaning from the kind of line used in a drawing.