Abstract: Substrates, particularly plastics, are preplated with metals by pretreatment of the substrate with phosphorus sesquisulfide in an organic solvent to deposit phosphorus sesquisulfide at the surface, followed by contacting the treated surface with a metal salt or complex thereof, to form a metal-phosphorus-sulfur compound. The substrate may be treated, either before or after its surface is provided with the metal-phosphorus-sulfur compound, with a water soluble organic compound selected from the group of the so-called water soluble organic etching compounds. Preferably the organic compounds are selected from the group consisting of di and mono ethers of water soluble glycols, di and mono ethers of water soluble di-glycols, water soluble carbonates, and water soluble lactones. Treatments of the surface of the substrate with these organic compounds renders the treated surface resistant to cracking.