It is shown how electrode surfaces can be decorated with small metal clusters that are formed via an STM tip. The process involves metal deposition from the solution onto the tip and subsequent transfer of metal from the tip to the substrate by an appropriate tip approach. With this process being fully automated, large mu m-size arrays of nanoclusters can be produced within minutes. It is demonstrated that the chemical nature of the substrate has a profound influence on the shape of the clusters. The stability of Cu nanoclusters on Au(111) and Ag(111) substrates has been studied as a function of potential and the dissolution kinetics followed with the STM.