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.