An article having an aluminum substrate, an unsealed, porous anodic oxide layer thereon and electrolytically deposited, randomly distributed discrete metal islands having a root portion anchored in one or more pores of the oxide layer. The metal islands extend from the root portion above the surface of the oxide layer in a bulbous, undercut configuration.A process for treating aluminum is also disclosed and includes the steps of electrolytically anodizing aluminum surfaced articles to form an unsealed, porous anodic oxide layer thereon followed by electrolytically depositing randomly distributed discrete metal islands in the pores of the oxide layer and extending above the surface thereof in the bulbous, undercut configuration.