Abstract: A method is provided for specifying and altering the electrical properties of fibers and fabrics. This allows the prescription of filter media prepared from these constituents for consistently optimum or near optimum performance in the collection of particulate matter. The method may include the steps of determining the triboelectric properties of fabrics having other desirable filter media characteristics, modifying the triboelectric properties of these fabrics as needed to preferentially selected properties and utilizing, selectively, modified fabrics as the filter medium for optimally attracting gas entrained electrically charged particles to the surface of the filter. The modification of the triboelectric properties may be realized chemically or by dyeing the fibers and fabric.