  Studies of random close packing of spheres have advanced our knowledge about
the structure of systems such as liquids, glasses, emulsions, granular media,
and amorphous solids. When these systems are confined their structural
properties change. To understand these changes we study random close packing in
finite-sized confined systems, in both two and three dimensions. Each packing
consists of a 50-50 binary mixture with particle size ratio 1.4. The presence
of confining walls significantly lowers the overall maximum area fraction (or
volume fraction in three dimensions). A simple model is presented which
quantifies the reduction in packing due to wall-induced structure. This
wall-induced structure decays rapidly away from the wall, with characteristic
length scales comparable to the small particle diameter.
