The paper explores the possibility of using periodic precipitation to
prepare anisotropic materials, on the basis of a numerical model of th
e time evolution and product distribution in periodic precipitates for
med by competitive particle growth. The model envisages a pre-existing
uniformly distributed material. After a time which depends on the sam
ple length and other system parameters, a nearly stationary state is r
eached, in which the band spacings and masses, and the radii of indivi
dual particles are indeed much more uniform than they are in systems w
hich depend primarily on reagent diffusion.