Ramping brightness down and blending toward a solid empties the canvas gracefully instead of a hard hush cut

The fade-to-black visual transition is triggered for an outro, or before a wholesale visual rewrite. Rather than a bare hush() that cuts the canvas abruptly, brightness is ramped down and the image is blended toward a solid color over successive saves, so the canvas empties gracefully. Raising the blend toward 1.0 over successive saves reaches full black; reversing the blend back toward 0 fades a new sketch in. The move gives a controlled, gradual clear that avoids the jarring cut of an abrupt hush.

Examples

src(o0).brightness(-0.6).blend(solid(0,0,0), 0.6).out() — push the blend toward 1.0 over successive saves to reach black; reverse toward 0 to fade a fresh sketch in.

Assessment

Why is a ramped brightness/blend fade preferred over a bare hush() for an outro? How do you use the same technique to fade a new sketch in?