As with all manufacturers of colored products, cosmetics companies use specialized measuring instrumentation to assist in quality control. However, cosmetics present unique challenges: Lipsticks and foundation creams are difficult to measure with contact instruments, and translucent shampoos and nail polishes require techniques that depend on more than just ordinary reflectance.
To complement standard instrumentation, some companies have collaborated with manufacturers to develop equipment to address specific needs. Using a broad range of photonic techniques, from optical microscopy and digital imaging to Raman spectroscopy, they also have produced some compact, attractive devices that are suitable for use in beauty salons and health spas, or on the cosmetics counters of retail stores...