After Effects Trim Paths: Animate Line Drawings Step by Step

Trim Paths is one of the most satisfying effects in motion design — it makes shapes appear to "draw themselves." Perfect for icons, logos, signatures, and decorative lines.

Basic Trim Paths animation:
1. Create a shape layer with a path (Pen tool, or draw a rectangle/circle)
2. Make sure it has a Stroke (and optionally no Fill)
3. In the shape layer, click Add → Trim Paths
4. Expand Trim Paths properties:
- Start: Where the visible portion starts (0% = beginning of path)
- End: Where the visible portion ends (100% = end of path)
- Offset: Rotates the start/end point around the path

Self-drawing reveal:
1. Set Start to 0%
2. Keyframe End from 0% to 100% over your desired duration
3. Apply Easy Ease (F9) for smooth motion
4. Your shape draws itself!

Self-erasing (draw on, then erase):
1. Keyframe End: 0% → 100% (draw on)
2. Then keyframe Start: 0% → 100% (erase), starting slightly after End finishes
3. The line draws on, then erases itself in the same direction

Multiple shapes with sequential timing:
Trim Paths has a "Simultaneously" option under its properties. Toggle to "Individually" and each sub-path within the shape layer draws separately.

Animating icons/logos:
1. Import your icon from Illustrator (as shape layers)
2. Select the shape layer
3. Add → Trim Paths to the top-level Contents
4. Animate End from 0% to 100%
5. Make sure all paths are stroked (no fills during the drawing phase)
6. After the draw completes, you can fade in the fills

Trim Paths on text:
1. Create your text layer
2. Right-click → Create Shapes from Text
3. Remove fills, add strokes to each letter path
4. Add Trim Paths and animate

Pro tip: After animating Trim Paths, add a slight taper to the stroke (available in newer versions of AE under Stroke → Taper). This makes the line drawing look like a real pen/brush stroke, with a thinner start and end. Alternatively, animate the Stroke Width alongside Trim Paths for a similar effect.