  A subset of a group is characteristic if it is invariant under every
automorphism of the group. We study word length in fundamental groups of closed
hyperbolic surfaces with respect to characteristic generating sets consisting
of a finite union of orbits of the automorphism group, and show that the
translation length of any element with nonzero crossing number is positive, and
bounded below by a constant depending only (and explicitly) on a bound on the
crossing numbers of generating elements. This answers a question of B. Farb.
