I am continuing to re- and re-read Schmid’s chapter on edges, because I’m not sure I have a decently full grasp of what he’s saying.
The book is Alla Prima: Everything I Know About Painting by Richard Schmid ($50 USD in soft cover from him; more from Amazon and more in hard cover).
Schmid begins his chapter by saying “Think about edges the way you would think about kissing someone…. Think of edges as exquisite subtleties, as the means to transmit romance, as ways to make your dabs or paint whisper or shout and reach nuances beyond the range of color. Think of them as visual poetry… but especially think of edges as you would the agents of expression in music….pianissimo (very soft), andante (flowing), allegro vivace (fast and lively), maestoso (majestic), fortissimo con sforzando (whamo!).