In accordance with the ISO 13655 standard, the “M” series of measuring mode settings were defined in order to standardize illumination conditions where optical brightening agents are utilized in substrates. The following is designed as a quick reference chart of the 4 different measuring mode settings within the “M” series. M0 “Color measuring mode A” spectral luminance factor without polarization filter under a light source that simulates standard illuminant A (gas lamps or LEDs, 2856…