After Effects Masks and Shape Layers

Control what’s visible on a layer with masks, and create standalone vector graphics with shape layers. Here’s how to do it in After Effects on macOS, step by step — part of the free After Effects beginner curriculum.

Lesson 5 of the After Effects curriculum. Before this: Effects and Effect Controls. Next up: Text Animation.

What you’ll do

• Select a footage or solid layer in the Timeline, then draw a rectangle mask with Q (or the Rectangle tool in the Tools panel) — the mask cuts out the layer, hiding everything outside it
• Understand mask modes: Add (default — shows inside), Subtract (shows outside), and how stacking multiple masks with different modes creates complex cutouts
• Adjust Mask Feather (F key with mask selected) to soften the mask edge; adjust Mask Expansion and Mask Opacity in the Timeline under the Masks property group
• Use the Pen tool (G) to draw a freeform mask path with custom vertices
• Animate the Mask Path property by enabling its stopwatch — draw a shape at frame 0, move to frame 60, reshape the mask, and watch it morph over time
• Deselect all layers in the Timeline (Cmd+Shift+A), then draw a rectangle with the Rectangle tool — this creates a standalone Shape Layer, not a mask
• Explore a Shape Layer’s contents in the Timeline: twirl open the layer to see the Shape Group, then twirl that to see Path, Fill, Stroke, and Transform properties
• Add a Trim Paths path operation to a shape layer (click Add > Trim Paths inside the shape group in the Timeline) and animate the Start and End values to draw on a stroke over time

Do it hands-free with Skilly

Reading steps is one thing; doing them while the menus are in front of you is another. Skilly is a voice-first tutor for macOS: you ask out loud — “where’s the masks panel?” — and it answers while moving your cursor to the exact button, watching your actual After Effects window. It’s the same After Effects curriculum these lessons come from, taught live instead of read. Free to start.

Keep going

This is one stage of the full After Effects beginner curriculum. Previous: Effects and Effect Controls. Continue with Text Animation.