I imagine you’ve all come across recommendations from artist/authors telling you to “link the darks”, or “connect the light shapes”. I know I had heard about the practice long before I understood what the benefits are. Is it a good idea? Always? What does it accomplish?
To put it simply, the idea is to have fewer shapes in the painting. Even if there are many separate objects in your composition, you can limit the visual confusion by connecting forms of similar value. The resulting larger shapes often make a bold, simple abstract pattern that co-exists with the content.