Abstract: A process of manufacture of a lattice configurated elastomer screen for classification, screening and washed of fragmented hard stocks of material. The process of manufacture of this lattice screen employs a cutting device with at least one rotary cutting blade. for extracting mutually spaced slots in the top and bottom layers of an elastomer sheet; with the top slots lying essentially above the bottom slots; being disposed transversely of one another. The top and bottom slots are cut at a common, intersecting depth of one another in the elastomer sheet: joining the bottom slots with the top slots; forming preferably rectangular apertures between the top and bottom slots areas of this lattice designed sifting body.