After Effects Tutorials / Filmmaking / Tutorials / Video Editing

Two Methods to Mask in After Effects

Jacob miller ot5kwzkh97s unsplash
Published 16 September 2020

Last updated on 22 February 2021

Using a mask in Adobe After Effects is one of those skills that form the basis of anyones After Effects knowledge. It’s a fundamental that has a wide range of applications and uses, and can really take your videos to the next level when used right.

As with any effect on After Effects, this one takes a bit of practice to master. However learning the basics for this is quick and easy, and you will be able to implement masks into your videos straight away.

Here are two methods to use a mask in Adobe After Effects:

Method 1 – Masking an image or video using the shapes tool

Using the “Shape Tool” located in the toolbar, we can create a mask using any of the shapes available to us.

  1. Firstly, go ahead and select the shape you would like your mask to be by clicking and holding down the shape tool at the top of your page. 
Masking using shape tool
  1. Make sure your video or image is selected in the composition, and go ahead and create your mask.
  1. Using the “Selection Tool”, double click on your mask and you can bring up the transform handles. Hold down shift and you can increase or decrease the size of your mask by dragging the transform handles inward or outward.
Masking using shape tool 2
  1. By hitting the drop down arrow of your mask in the composition, you can play around with the various mask options like feathering the mask for a softer edge, or expanding the mask. You can also change the mask mode from add to subtract, or any of the others to suit your needs.

Tip: when creating your mask using the shape tool, hold down shift to get a perfect shape.

Method 2 – Masking an image or video using the pen tool

By using the “Pen Tool”, we can create a more intricate mask to whatever shape you prefer.

  1. Go ahead and grab the pen tool and begin defining the shape of your mask. You can hold down the alt or option key to use the tangent handles for where your mask needs to curve.
  1. Once you have created your full shape by joining the last point of your mask with the first, the mask will perform its function by masking out the defined areas. 
Masking using pen tool
  1. At this point you can head down to your mask within the composition, and again, click the drop down arrow to bring up the various mask options.
  1. If the area you have created your mask around is going to be moving, you’ll need to animate your mask using key frames and adjusting the mask shape and size to each frame.

Tip: You can use mask tracking to track your mask throughout your clip. Head up to “Animation”, and select “Track Mask”. From here, select your tracking method and click the play button to allow After Effects to analyse your mask path.

Mask tracking
Mask tracking method

The uses for masks are wide ranging, but by adding the basics to your repertoire, you can customise it to best suit your needs.