At some point in any motion graphic project, you will need to use one or multiple After Effects mask in your composition and I have to say even after 10 years of motion graphic experience I am still learning new tips and tricks to work with masks. I’ll show on this tutorial the basic and advanced techniques to use After Effects mask, so by the end of this article you will know how to use and more be comfortable with the AE mask shape and mask layers.

Below a list of mask subjects, so you can jump straight to the section you prefer.

  1. What is an After Effects mask?
  2. Type of masks in After Effects?
  3. How to create a mask in After Effects?
  4. How to modify a mask in After Effects ?
  5. How to use the Mask Modes in After Effects?
  6. How to create a Shape Layer Mask in After Effects?
  7. Draw with the Shape Tool in After Effects
  8. Trace Mask with the Pen Tool in After Effects
  9. How to edit and modify a shape layer mask?
  10. How to create a custom mask in After Effects?

1. What is an After Effects mask?

Essentially a mask in After Effect is a shape that hide or show a specific area of a layer (or multiple layers) on your composition. Specifically a mask is a path / outline made of vertices that you can adjust or/and animate.

2. Type of masks in After Effects?

There are 2 type of masks you can use in After Effects
– regular mask
– shape layer mask.

After Effects mask compare to shape layer mask

TIPS: Something you must know when you create a mask 
If your select your layer on your timeline: You will create standard mask
If your don’t select your layer on your timeline: You will create a shape layer mask

Regular mask are often used for rotoscoping and morphing because you can quickly mask multiple frame.

3. How to create a mask in After Effects?

– Select your image/video on your timeline
– Top tools bar, click on the shape tool icon after effects shape tool icon (Shortcut: Press Q)
– In you composition draw your rectangle mask on your image/video

After Effects regular Mask demo example below

TIPS:
If you want to turn ON and OFF the visibility of your mask outline and shape path, you can use the Toggle Mask and Shape Path visibility icon Toggle Mask and Shape Path Visibility icon
located on the bottom of your composition.

4. How to modify a mask in after effects ?

There are many ways to modify after effects masks I will go over the essential below

Move one mask point at a time

Select the layer on your timeline
Press V (Selection tool)
Start moving each point

Move Multiple mask points at once

– Select the layer on your timeline
– Press M (Shortcut to access the mask properties)
– Select Mask Path
– Press V (Selection Tool)
– Click on one point/vertex
– you should be able to move all the point together

Resize or Rotate a mask

– Select the layer on your timeline
– Press M (Shortcut to access the mask properties)
– Select Mask Path
– Double click on any point/vertex
– Move your cursor on the corner of the layer you should see the resize cursor which should allow you to scale.
– Press Shift if you want to scale proportionally.

If you move you cursor further more on the corner you should also see the rotate cursor which will allow you to rotate your mask.

5. How to use the Mask Modes in After Effects?

After Effects have 7 mask modes options click on the drop down you will see: None, Add, Subtract, Intersect, Lighten, Darken, Difference
After Effects Mask Modes options

See below what After Effects mask mode options are doing visually