The printed calibration area may be otherwise referred to as a “test patch” or “test area”. The printed calibration area may be used to calibrate the printing system 100. The printed calibration area corresponds to a given colorant in a set of colorants printable by the printing system 100. A colorant may be otherwise referred to as a “printing fluid”. A colorant may correspond to a given base color, where other colors may be formed from combinations of colorants. Examples of base colors include, but are not limited to, cyan, magenta, yellow, red, green and blue and black. In some examples, a plurality of calibration areas are printed, each corresponding to a different colorant in the set of colorants. In one example, the set of colorants comprises 4 colorants. In another example, the set of colorants comprises 7 colorants. In another example, the set of colorants comprises 15 colorants. The number of colorants in the set of colorants is less than the number of possible colorant combinations, e.g. NPs. A plurality of patches may be printed for a given colorant. In some examples, 16 patches are printed for a given colorant in the set of colorants. Different patches may correspond to different amounts of the given colorant.