When irradiated, a mixture of (a) a non-volatile substance containing at least one olefinic double bond and (b) a dibenzalacetone palladium complex deposits zero-valent palladium. Electrically non-conductive carrier materials which have been coated with a layer of said mixture can, after irradiation, be metallized by metal deposition without current, with electrically conductive coatings or patterns being obtained.