Kit contains a 20-step reflection grayscale ( 0.10 increments from 0.0 white to 1.90 black )printed with neutral inks on a plasticized substrate. Also includes a set of process-color patches containing the four primaries plus two-color and three-color overprints to Standard Web Offset Process (SWOP) standards. For traditional photography the guides are useful in film testing for color and density, from copying artwork or as a reference for tabletop photography. The guides can also be used in digital capture or scanning to assist in calibration and creating profiles. The substrate for the grayscale and color patches is stable and neutral, and is flexible for mounting on a scanner drum. Guide measures 8" wide.