Set of two flexible check cards takes guessing out of setting perfect exposure and color balance, that can only be archived with high quality Mennon Gray Cards with the uniform spectral reflectance, regardless of wavelength, color or intensity of the illumination. Each card has two sides: one side white and other is gray. The gray side used as a reference area for exposure metering while the white side enables correct white balance that is so important in digital photography. Specification: * Gray side: Reflectance 17.8%; Density 0.74 * White side: Reflectance 92.0%; Density 0.036 * Max. deviation of reflectance: 2% * Max. error in exposure measurements: 1/8 of F-stop * Card sizes: 6"x8" and 8"x10" * Core material: high density paper based composite * Gray side material: special paper with spectrally flat 18% coating * White side material: special paper with spectrally flat 18% coating