What a watermark is for
A watermark does not make a video impossible to steal — nothing does. What it does is make an unauthorised copy carry your name wherever it travels, which discourages casual reposting and gives you something concrete to point at when it happens anyway. That is a modest goal, and it is worth being clear about it, because a watermark heavy enough to genuinely prevent reuse also ruins the video for the people you meant to watch it.
Placement matters more than size
A corner is conventional because it stays out of the way, but corners are also the easiest thing in the world to crop off. If the video is genuinely at risk of being taken, the centre — at low opacity — is far harder to remove, at the cost of being visible throughout. Most people want the bottom right and a moderate opacity, which is what this defaults to.
Proportions, not pixels
The watermark size and its distance from the edge are both expressed as fractions of the frame. A watermark set in pixels looks correct on the clip you tuned it against and wrong on everything else — enormous on a 480p export, invisible on 4K. Setting it proportionally means one choice works across every resolution you might publish at.
Why the text has a shadow
White text over a bright sky is invisible, and black text over a night scene is equally lost. A soft dark shadow behind the glyphs solves both cases at once and is the single reason a watermark stays legible across a whole video rather than only across the shot you previewed. It is applied automatically.
Keep the original
The watermark is composited into every frame and then encoded, so it is part of the picture from that point on. There is no layer to remove and no undo on the exported file. Always watermark a copy.