You can create a fade from black (fade-in) by adding a dissolve at the beginning of the first segment on a track or at the beginning of a segment preceded by a gap. Likewise, you can create a fade to black (fade-out) at the end of the last segment on a track or at the end of a segment followed by a gap.
The following procedure shows how to create a fade from black. To create a fade to black, follow the same instructions but work at the end of the video clip instead of the beginning. Note that head and tail frames are not needed for fades, as the first frames of the segment are used.
A dissolve is added using the default duration. The alignment is set automatically to From Cut.
Creating a Fade on Multiple Timeline Tracks
You can add a fade-in or fade-out to both video and audio tracks simultaneously on the timeline.