Mitsuki – Mikaeshi (見付き – 見返し) – in the context of finished materials such as a counter top or door frame, the “visible” side and “less visible” side (or ultimately invisible side in some cases), respectively.
It is often the case with natural wooden products, that one side will naturally be more aesthetically pleasing than the other. Natural boards also tend to cup or crown slightly. Larger objects placed on built-in desktops or shelves for example, may tend to rock back and forth on a crowned surface, as opposed to a cupped one.
In this way, you can arbitrarily place higher importance on one of the sides when varnishing, sanding, etc, without having to treat both sides equally.