on which the molds and stampers are electroformed is subjected to demagnetization prior to electroforming to prevent tramp metal particles from adhering to the surface of the matrix and thereby causing microdefects in the electroformed parts application_number US 30701181 A description nickel is one of the most commonly used metals employed in the matrixing process used for the manufacture of the masters molds and stampers employed in the record manufacturing art other commonly used metals are for example nickel alloys iron alloys and the like the metals which are commonly used for the electroforming of the matrixes and in particular nickel have the capability of becoming magnetized under the conditions encountered in the electroforming process in an effort to determine the cause of microdefects found in the molded records an evaluation was made of the properties of the matrixes used in the electroforming process as well as the plating baths wash baths and the overall environment in the plating area as a result of this investigation it was found that the masters molds stampers are often formed in the electroforming process with zones of relatively high magnetism referring to fig1 there is illustrated a typical matrix 10 having an edge portion 11 a grooved recorded.