Abstract: A method of selectively depositing a metal on a surface of a substrate is disclosed. A suitable substrate is selected and a surface is treated with a desensitizer selected from the group consisting of (a) hydrazine, (b) a substituted hydrazine having the structural formula ##STR1## where R.sub.1 is an organic radical selected from the group consisting of alkyl, cycloalkyl, aryl, alkaryl, aralkyl, alkoxy, aryloxy and heterocyclic radicals and R.sub.2, R.sub.3 and R.sub.4 are the hydrogen radical or are the same as R.sub.1, and (c) a mixture of the foregoing. The desensitizer-treated surface is selectively exposed to a source of ultraviolet radiation to render selected areas thereof incapable of desensitizing a sensitizing species. The radiation-exposed surface is treated with a sensitizing species to sensitize the selected areas.

Abstract: A pattern capable of reducing thereon a precious metal is generated on a suitable substrate by first coating selected portions of the substrate with a solution, called a photopromoter, which contains a metal salt. The metal salt possesses two characteristics:(a) the oxidation state of the salt (i.e., of the metal ion) is alterable (either increasable or decreasable) by exposure of the salt to radiation of the proper wavelength; and(b) in either the original or the altered oxidation state (but not in both states) the salt is capable of reducing a precious metal, e.g., a metal of the platinum group such as palladium, platinum or rhodium, from a salt thereof.The photopromoter-coated substrate is next selectively exposed to the proper wavelength radiation to produce a pattern of the photopromoter salt capable of reducing the precious metal. The remainder of the salt is incapable of reducing the precious metal.