Watermark an image

No, and it's worth being clear about that before you spend time on placement. A watermark is a deterrent and an attribution, not a protection. Anyone determined can crop it, clone it out, or paint over it, and the tools for doing so are free and take about a minute.

What it does well is different and still valuable. It stops casual reuse, where somebody drags an image into a deck or a blog post without thinking. And it travels with the picture, so when the image turns up somewhere without a credit, your name is still on it.

Where to put it

A corner is the least intrusive and the easiest to remove. Fine when the purpose is credit rather than deterrence.

Across the middle, larger and semi-transparent, is much harder to remove cleanly because it sits over the subject. It also makes the image less pleasant to look at, which is exactly the trade: a proof copy is meant to be usable enough to judge and not usable enough to publish.

Tiled across the whole picture is the strongest and the ugliest. Right for proofs and previews, wrong for anything you want people to enjoy.

If you're choosing a corner, avoid the bottom right by default. It's the first place people crop, because it's where watermarks always are.

Opacity

Somewhere between 25 and 50 percent is the useful range for a visible mark.

Below about 15 percent it becomes decorative: hard to read, easy to remove, and it still degrades the image. Above about 60 it dominates the picture.

The test is whether the mark is legible when the image is displayed small. A watermark you can only read at full size does nothing on a thumbnail, which is where most images are seen.

What a watermark can't do

It can't prove ownership. Anyone can put any name on any image. If ownership matters legally, the useful things are the original raw file, the capture date in the metadata, and a registration where your country offers one.

It can't survive a screenshot of a crop. Nothing visible can.

It can't stop a model removing it. Software that erases watermarks is ordinary now, and a semi-transparent mark over a busy area is the hardest for it, which is another argument against the tidy corner.

Metadata is the quieter option

Copyright and contact fields can be written into the file itself, where they're invisible and survive being copied. Plenty of platforms strip them on upload, which is the catch, but for files you send directly to a client or an agency they persist and cost nothing visually.

Doing both is reasonable: a visible mark for the public copy, metadata for everything.

Practical settings

For a proof sent to a client: tiled, 30 percent, plainly readable. It should be uncomfortable to publish.

For a photo posted publicly: a corner or small mark, 30 to 40 percent, at a size that stays legible in a feed.

For a stock preview: across the middle, large, 25 to 35 percent.

The original

Watermark a copy, always. The mark is drawn into the pixels and there's no undo, so a watermarked file is a one-way result. Losing the clean original to a careless overwrite is a much bigger problem than any reuse a watermark would have prevented.

Everything happens in your browser, so the photograph isn't uploaded, and there is no limit on how many you do at once.