I’ve only been playing with Synfig for a couple days, but I’ve read a bunch and haven’t seen this anywhere.
When dealing with gradients in open areas fade your gradients to zero alpha to keep it from overwriting its surroundings.
Here’s a black rectangle and two gradient curves. Nothing has been done to constrain the gradients from overflowing, except for the addition of the transparent areas within the gradient.
Like I said, I hadn’t seen this documented anywhere. So I’ve stuck it into the wiki!
Being my first ever wiki edit, I’m not really happy with it at all. I would be much more comfortable if one of you old timers played with it a bit. Maybe added some kind of format, and stomped my verbology into compliance.