Abstract
Let G be a reductive complex algebraic group and V a finite-dimensional G-module. From elements of the invariant algebra C[V](G) stop we obtain, by polarization, elements of C[kV](G) stop, where k >= 1 and kV denotes the direct sum of k copies of V. For G simple, our main result is the classification of the G-modules V and integers k >= 2 such that polarizations generate C[kV](G) stop.