The present invention provides a non-toxic shampoo concentrate that generates colored lather when it is mixed with water. A plurality of contract parameters of the proposed contract are received. The method includes the steps of determining an operating mode of the cut substrates; sorting the cut substrates and supplying the sorted cut substrates to one of the plurality of cassettes according to the operating mode of the cut substrates determined in step ; and repeating steps and for a predetermined lot number of cut substrates.