Fig. 1.

Methods used for making particles with different shapes can be categorized into two general schemes. (Upper) Scheme A involves liquefaction of particles by using heat or toluene, stretching the film in one or two dimensions and solidifying the particles by extracting toluene or cooling. The example shown here produces elliptical disks. (Lower) Scheme B involves stretching the film in air to create voids around the particle, followed by liquefaction using heat or toluene and solidification. The example shown here produces barrels.