Ion-exchange in surface-initiated polyelectrolyte brushes provides a versatile route to the formation of catalytically active surfaces for electroless deposition of Cu. The advantage of this procedure is the covalent anchoring of the catalyst support layer, eliminating delamination of the metal film, even when deposited onto PDMS substrates. Furthermore, by tuning the concentration of PdCl42- ions in the brushes, the rate of deposition and hence the thickness of the overall film can be controlled easily.