Light-cone distribution amplitudes (LCDAs) for B-mesons in heavy-quark effective theory (HQET) provide one of the essential non-perturbative inputs entering QCD factorization theorems for exclusive B-decays. In this talk, I show how to derive the eigenfunctions of the Lange-Neubert evolution equation which governs the behaviour of the B-meson LCDAs under a change of renormalization scale. The spectrum of the LCDA with respect to these eigenfunctions defines a “dual” function which renormalizes multiplicatively. In terms of these dual functions, renormalization-group improved factorization formulas take a very simple form. I also report on how to implement perturbative constraints from the operator product expansion in HQET within the new formalism.