2-Line Direction

Directional lines allow paintings to have horizons with "horizontal" lines, "vertical" lines allow separation in piano keys, but diagonal lines a bit different. They cross the canvas or page a bit different. They bing your eyes to focus on an object or away from something. Bringing objects to life or detailing.

In this picture the lines create an interesting scene and make your eyes run across the page like wild fire. The lines add life to the picture horizontal and vertical lines can not.