The present invention provides a method for preparing a conforming shield enclosure for shielding a semiconductor device of an electronic component assembly comprising the steps of: (a) metalizing a sheet of a thermoformable polymer with an admixture of a conductive metal and a resin; and (b) thermoforming the metalized thermoformable polymer from step (a) to form a conforming shield enclosure; wherein the conforming shield enclosure has dimensions conforming to the inside of a housing of the electronic component assembly and enclosing and thereby shielding the semiconductor device from electromagnetic frequencies, wherein the conforming shield enclosure is prepared by paint metalization.