In this tutorial, we will show you how to create an animated letterbox effect, often seen in various YouTube videos, using Adobe Premiere Pro. This effect is popular for signaling a cinematic sequence to the audience.

**Step 1: Set Up Your Sequence**
Open your sequence in Premiere Pro and position your frame to preview where the black bars will appear. This will help you visualize the letterbox effect.

**Step 2: Add a Black Solid Layer**
Create a black solid layer on top of your footage. This layer will be used to create the letterbox bars.

**Step 3: Apply a Mask**
Go to the Effects Control panel and use the Four-Point Polygon Mask from the Opacity tab to mask the black solid layer. Set the Mask Feather to zero to ensure sharp edges.

**Step 4: Animate the Letterbox**
Adjust the Mask Expansion to animate the letterbox bars. This will create the effect of black bars coming in and out from the top and bottom of the screen.

For a detailed, step-by-step guide on creating this animated letterbox effect, check out the full video tutorial.