Refining transitions

Now whenever I create an animation, I kind of like to think of it like a song.…You know how you have an intro and verses and chorus and the conclusion?…Well, in here we have an intro, and…we have our transition, and we have our conclusion.…So I want to focus on blending a…transition in between each of these different sections.…So we'll start right up at the beginning.…Let's add a quick fade to our paint drops here.…So select layer two, and just press Option+t on the Mac…or Alt+t on Windows to create a key-frame for the opacity.…

And we'll just drag that value down to zero.…Let's just have this be a ten frame fade.…So I'll just move ten frames down the timeline there.…And scrub up to 100%.…So, right off the bat, we've transitioned our start.…It's sort of looks like the paint's, sort of,…just flying in from the top of the screen.…Now,…right about here in the transition from our paint to our vortex, I want these…lines to appear that we created earlier. So let's go ahead and collapse layer two.…And turn the visibility on for layer three and as…