Having spent time around great live sound engineers, I’ve often heard that the best sound techs are the ones who are invisible. The moment something goes wrong (mic feedback, a sudden pop) the audience is pulled out of the moment.
Editing works the same way. Small distractions pull viewers away from the main focus.
Recently, while editing a social media post, I noticed a subtle distraction: the caption box shifted up and down a few pixel depending on the text within it.
Whenever a caption included capital letters or characters with descenders (like “p” or “g”), the bounding box shifted up or down a few pixels. Premiere was resizing the box based on the text height. The result wasn’t dramatic, but it created a small visual “jump” from caption to caption.
Having spent time around great live sound engineers, I’ve often heard that the best sound techs are the ones who are invisible. The moment something goes wrong (mic feedback, a sudden pop) the audience is pulled out of the moment.
Editing works the same way. Small distractions pull viewers away from the main focus.
Recently, while editing a social media post, I noticed a subtle distraction: the caption box shifted up and down a few pixel depending on the text within it.
Whenever a caption included capital letters or characters with descenders (like “p” or “g”), the bounding box shifted up or down a few pixels. Premiere was resizing the box based on the text height. The result wasn’t dramatic, but it created a small visual “jump” from caption to caption.
Not a big deal, right? But my editor brain knew there must be a cleaner method. So I moved the captions into After Effects.
First, I created a simple black rounded box using a shape layer. Then I created a text layer and set the anchor point to the bottom of the text baseline. That ensured the text itself wouldn’t shift vertically.
Next, I used a simple expression so the box would resize horizontally with the text but keep a fixed height. Here’s the expression added to the box’s Size parameter (generated with a little help from Claude):
s = thisComp.layer("Text");
w = s.sourceRectAtTime().width;
padding = 80; // Side padding
fixedHeight = 80; // Locked height
[w + padding, fixedHeight]This keeps the width flexible while locking the height, preventing that subtle vertical movement.
To keep the text centered within the box, I added a second expression (to the box’s Position parameter):
s = thisComp.layer("Text");
rect = s.sourceRectAtTime();
x = rect.left + rect.width / 2;
y = -10;
[x, y]With that working, the final challenge was getting my existing captions into After Effects without retyping them.
I discovered an excellent plugin called QuickCaption, which imports an SRT file directly into AE as a single text layer that updates the source text based on the caption timing.
Brilliant.
In the end the setup was simple:
• Text layer – containing the full SRT captions
• Box layer – the rounded rectangle driven by expressions
From there I used Dynamic Link back to Premiere, though exporting would work just as well.
And just like that, the problem disappeared. The captions now stay perfectly stable from line to line. Nothing jumps. Nothing shifts. Reading them feels calm and consistent.
It’s a small detail most viewers will never consciously notice. But that’s the point.
Like great live sound, the best editing work often goes completely unseen.
It’s the sound tech’s job to prepare for what could become a distraction, and to remove the feedback.