Once you have built a printer profile using ColorMunki, you have the option to improve its performance further through optimization. You can perform this optimization step as many times as you wish and the profile performance will get incrementally better. This option only works with profiles built with ColorMunki.

To optimize profiles, go to Profile my Printer and select Optimize Existing Profile in Step 1 of the wizard.

Optimization of a profile involves the extraction of colors found in an image you specify, and producing a customized color test chart, which you print and then measure using your ColorMunki device. The measurements are then used to improve the performance of the profile.

Each time you perform an optimization, we recommend choosing a new image that contains a variety of different colors than previous images, in order to get the most benefit from optimization. If you optimize with images that contain mostly green colors, then the profile will have improved accuracy in green colors. If you optimize with images that contain mostly skin tones, then the profile will have improved accuracy reproducing skin tones. If you optimize with images containing neutrals, the profile gray balance performance will improve.

Optimizing the existing profiles does not actually make black and white profiles. It takes an image and samples a collection of colors from it.  A lot like when you use that image in the palette tool. These sampled colors are then printed, measured and the optimized in the profile. If you need a profile that is optimized for portrait work, select an image with a variety of flesh tones. ColorMunki will create a collection of fleshtone samples to use for the optimization. You can take the same original profile and create several optimized profiles for specific applications such as landscapes or grayscale images. 

The profile is not technically a grayscale profile, it is simply a profile that is optimized for several shades of grey (from a grayscale image).