Image Mask and Paint Stroke in Motion

Create an Image mask and Convert the Animated Brush Stroke to a Mask:

• Right click the object you'd like masked (in the Layers tab)
• Select "Add Image Mask" from the contextual menu
• Drag the animated stroke (e.g. Liquid, Ink Bleed 01 Heavy) onto the Image Mask layer (in the Layers tab)

Painting with Motion

Select Paint Stroke Tool
Open the HUD to review the paint stroke options

• the "Write On" option will add animation to the static stroke
• Change the Width to 50 pixels

Open the Shape tab in the Inspector window

• Select a new shape style: some styles are static (show the whole stroke at once) and some are animated (e.g. Ink Bleed 01 Heavy, Ink Bleed 02 Taper, Ink Bleed 03 Drops, Ink Dilate 01, 02, 03, 06, Light Streak, Light Tail, Ants, Chocolate, Smoke 01, Splatter 01, Wood Shavings 01, 02, )
• Change the brush color
• Change the brush opacity to show more dimensional