Track mattes

- Masks are a great way to hide or reveal … portions of our layer. … But what if we wanted to have one layer … cut out another layer? … We can use what are called Track Mattes … and we'll see how we can use them here … to hide or reveal parts of our characters. … In this composition, I've got an animated texture … and it's called "Fiesta". … It's just a bit of confetti bouncing around. … But if I come over here to preview my Alpha channel … indicating that it's all opaque. … and let's introduce some transparency. … and then come over to our rectangle tool. … And then we'll click and drag to create a brand new mask. … And under the mask feather property … I'll click this icon so we can unlink the proportions. … This way I can introduce feathering … just on the vertical axis only. … Now if we go back into Alpha channel … you can see that we've introduced this gradient. … Everything that's black is transparent. … You can see right through it. … Everything that's white is opaque. … In fact, if we come down here to this icon …