An effective pretreatment of polymers is crucial for achieving a good adhesion of metal coatings to the substrate. We have characterised the individual stages bf a swell and etch treatment of epoxy resins with a variety of techniques, Scanning force microscopy (SFM) investigations have enabled an quantitative assessment of the swelling and chemical etching of the polymer. Information about the chemistry of the process has been obtained using gravimetric measurements, photoelectron and infrared spectroscopy.