Positively charged (cationic) polymers are one of the most important types of polymers used in haircare products. Because of their high degree of substantivity to hair, they are useful in shampoos and conditioners. Numerous studies have shown that cationic conditioning compounds protect against hair damage caused by cosmetic chemical treatments and grooming practices. When hair care products are being developed, it is crucial that formulators determine the depositional characteristics of the polymer from a functional as well as a cost perspective. Microfluorometry can be used to quantitatively determine the amount of a polymer deposited on the surface of hair fibers and to determine the extent the polymer penetrates into the hair fibers. The data output is the fluorescent intensity obtained from scanning along a predefined length of hair fiber.