Starting with an original sculpture which Nelles makes out of wax, wood, metal or resin, he makes a series of molds until he creates a master pattern called a matchplate. Special molding sand is rammed on this pattern to make a sand mold. Molten bronze is then poured into the mold at 2150 degrees F. Many hand finishing operations go into each casting. Grinding, cutting, sand blasting, and tumbling, are all employed before a final patina finish is applied. All of the artist's casting designs are made in his studio foundry.