  We investigate the formation of stripes in $7\chunks \times 6$
  Hubbard ladders with $4\chunks$ holes doped away from half filling using the
density-matrix renormalization group (DMRG) method. A parallelized code allows
us to keep enough density-matrix eigenstates (up to $m=8000$) and to study
sufficiently large systems (with up to $7\chunks = 21$ rungs) to extrapolate
the stripe amplitude to the limits of vanishing DMRG truncation error and
infinitely long ladders. Our work gives strong evidence that stripes exist in
the ground state for strong coupling ($U=12t$) but that the structures found in
the hole density at weaker coupling ($U=3t$) are an artifact of the DMRG
approach.
