a filter frame and media capable of withstanding repeated heating to high temperatures in an oxidizing environment , and a method of cleaning the same for indefinite use in a method of operating industrial paint booths . progressive density , heat resistant , and preferably metal media paint booth filters are provided for replacement of existing filters in industrial paint booths . the filters are structurally resistant to cyclic heating to high temperature in an oxidizing bake - off oven where the paint residue accumulated on the filters is reduced to ash . after cooling , the ash is removed , and the filters returned to service , and the cycle is repeated . the filter comprises a frame section and a mesh media section which has a plurality of mesh portions . the mesh portions are preferably arranged in a series m 1 , m n - 1 , m n , wherein n is a positive integer of 4 or more , that are sized with the free face area a n of each mesh portion n so that the overall mesh media section has a progressive density characteristic . thus , an excessive amount of material is not captured at the first mesh portion m 1 so as to avoid &# 34 ; face blinding &# 34 ; of the filter . in paint booth operation , when the filter has completed its operating cycle , typically as determined by a air flow velocity , dirty filter elements are removed and the filter is heated remove paint residue , and producing ash . after cooling and ash removal , the filter is returned to service .