Ultrasonication reduces the plating time for electroless deposition of copper onto microporous membranes. Ultrasonication also helps eliminate the need for pretreatment or chemical etching of the membranes. Electroless plated materials have high enough bulk conductivities (up to 0.82 S cm(-1)) to give electromagnetic shielding efficiencies of 55 +/- 5 dB in the frequency range 10 kHz to 1 GHz.