TCF allows for an economy of drawing effort. The art on the left ended up with an unattractive jaw line, or so my wife said; so I photocopied it (which saves the original). Then I drew the art on the right over/on top of the art on the left on the photocopy. In this way an artist can create multipl copies of the same work and where each is sufficiently differentl to be considered a new work of art. This idea will help a starving artist survive.