Fluorescence micrographs of hair fibers measure the amount of cationic material, such as 18-MEA, present on the hair surface. Fluorescence micrographs of bleached hair fibers treated with the SLS-1 shampoo alone or an SLS-1 conditioning shampoo containing 1.5% active Cutissential 18-MEA 40 are shown in Figure 5a and 5b, respectively.