  The magnetotransport properties of antidot lattices containing artificially
designed grain boundaries have been measured. We find that the grain boundaries
broaden the commensurability resonances and displace them anisotropically.
These phenomena are unexpectedly weak but differ characteristically from
isotropic, Gaussian disorder in the antidot positions. The observations are
interpreted in terms of semiclassical trajectories which tend to localize along
the grain boundaries within certain magnetic field intervals. Furthermore, our
results indicate how the transport through superlattices generated by
self-organizing templates may get influenced by grain boundaries.
