The different modes for keeping drawings visible for multiple frames
It is sometimes useful to make sketches persist for multiple frames during playback; for example you may wish to preview the timing of sketched keyframes, or you may wish to sketch using many frames as a reference.
There is a mode to display drawings until the next one appears. You will find the Hold Sketches menu in the player (the H icon) and it works like this:
Add to Current Sketch
Anything you draw will be held on subsequent frames. If you draw on subsequent frames the strokes will be added to the active drawing. In this way you can create a single sketch using a range of frames.
Add New Sketch
Anything you draw will be held on subsequent frames. If you draw on subsequent frames, it will automatically spawn a new image annotation, replacing the previously held sketch during playback. This mode is good for previewing timing of sketched keyframes.
Anything you draw is only visible on the frame you drew it on.