We show that the structure of a substrate pattern drastically influences th
e nature of surface freezing. By using phenomenological theory and computer
simulations of a hard sphere fluid next to a substrate formed by a periodi
c array of fixed spheres, we find that a pattern which is commensurate with
the bulk crystal induces complete surface freezing through a cascade of la
yering transitions. A rhombic pattern, on the other hand, either generates
a crystalline sheet which is unstable as a bulk phase or prohibits surface
freezing completely.