The invention relates to mouldings having an optical effect which
essentially consist of core/shell particles whose shell forms a matrix
and whose core is essentially solid and has an essentially monodisperse
size distribution, where a difference exists between the refractive
indices of the core material and of the shell material. The mouldings are
characterized in that they are obtainable by a process in which the
core/shell particles are heated to a temperature at which the shell is
flowable, and the flowable core/shell particles are subjected to the
action of a mechanical force.