The effect of a catalytic surface activation on the electromagnetic interference shielding of Cu deposited polymer substrates was investigated. The surface of polymer substrates was catalytically activated by different methods respectively adopted Pd aerosol nanoparticles and Sn-Pd wet chemical processes. Although both activations initiated the deposition of Cu on the substrates, differences such as morphology (Pd aerosol: similar to 80 nm vs Sn-Pd: similar to 140 nm, in Cu grain size) and composition (Pd aerosol: Cu and Pd vs Sn-Pd: Cu, Pd, Sn, and Cl) of Cu deposits were presented. Specimens activated using Pd aerosol nanoparticles showed a higher range of shielding effectiveness by about 4-10 dB than those activated by Sn-Pd processes in 2-18 Ghz frequencies. (C) 2011 Elsevier B.V. All rights reserved.