Image Overlay

How to use the image overlay

1. Choose a background image and an overlay image.
2. Set the anchor, size, margin and opacity, and pick a blend mode.
3. Download the composite as a PNG.

About this tool

Putting a logo in the corner of a photograph, a texture across an illustration or a signature onto a scan is the same operation each time: draw one image over another at a chosen position and size. This does that, at the background image's full resolution, and exports a PNG.

Size is a percentage of the background's width rather than a number of pixels, which is the detail that makes settings reusable. The same logo exported at 500 pixels and at 2000 places identically, because the calculation never consults the overlay's own dimensions — so a set of images can be given a consistent mark without adjusting for whatever file happened to be to hand.

Blend modes are offered with an explanation of what each is for rather than as a list of names. Multiply darkens and makes white disappear, which is what a signature or an ink stamp needs; screen does the opposite and suits glow and light leaks; difference turns identical images black, which is how it is used to compare two versions of the same picture.

When the overlay extends past the edge of the background, the page says so. Canvas clips silently at the boundary, and a mark half off the corner is easy to miss in a scaled-down preview and obvious in the exported file.

Common uses

• Adding a logo or watermark to a photograph.
• Placing a signature image onto a scanned document.
• Comparing two renders using the difference blend mode.

Frequently asked questions

Is the exported image full resolution?

Yes. The preview is scaled to fit the page, but the export keeps the background image's original pixel dimensions and nothing is downsampled.

Why is the overlay size a percentage?

So the same setting works regardless of the overlay file's own resolution. A logo at 500 pixels and the same logo at 2000 place identically.

What does the multiply blend mode do?

It darkens, and white in the overlay disappears entirely. That is what makes it the right choice for a signature or a stamp scanned on white paper.