  We demonstrate that surface morphogenesis in compressed thin films may result
from spatially correlated plastic activity. A soft glassy film strongly
adhering to a smooth and rigid substrate and subjected to uniaxial compression,
indeed, does not undergo any global elastic pattern-forming instability, but
responds plastically via localized burst events that self-organize, leading to
the emergence of a series of parallel ridges transverse to the compression
axis. This phenomenon has been completely overlooked, but results from common
features of the plastic response of glasses, hence should be highly generic for
compressed glassy thin films.
