Put a signature on a photo

A signature arrives as a photograph of paper, not as a transparent file, so the first thing it needs is the paper taken away. This stage opens with the colour key already on white — tolerance 18, softness 12 — and the Mask tab in front, with the ink colour control beside it.

It places a signature on a photograph — a print, a certificate scan, a picture that needs signing. It does not make standalone signature files for a form upload, which have their own pixel and KB rules.

1. 1Open the photo. The photo the signature goes on. It is read here and goes nowhere.
2. 2Add the signature. A phone photo or scan of the signature on plain white paper. It lands lower right at 22% of the width with the white already knocked out.
3. 3Clean the paper away. If grey paper is left, raise the tolerance or press Pick the colour and touch the paper. Decontaminate on the same tab takes off a pale or grey edge.
4. 4Choose the ink. Switch on Recolour to one ink and pick black or blue — grey biro becomes one clean colour with its own edges.
5. 5Place it and save. Drag, turn and size it, then save at full size.

Opens

Lower right, 22% of the frame's width, inside a 3% margin.

Paper

Colour key on white, tolerance 18, softness 12; colour, tolerance and softness adjustable.

Ink

Off, black, blue or any colour; every stroke keeps its own alpha.

Edge

Decontaminate 0–2 px: erodes the edge and takes its colour from the strokes beside it.

Saving

PNG, JPG or WebP at full size.

• Shadows and folds in the paper are not white, so they stay. Photograph the signature flat, in even light, filling most of the frame.
• This puts a signature on a photo. It does not produce the separate signature file a form portal asks for.
• A very faint pencil signature can be keyed out with the paper. Use a dark pen.

Why does the paper disappear?

The colour key removes every pixel close to the paper's colour — white here, unless you pick another — and fades the ones near the edge of that range so the strokes do not end in a staircase. Ink is far from white, so it stays.

My signature has a grey edge — why?

The pixels where ink meets paper are a mix of both. Raise Edge softness a little, then use Decontaminate on the Mask tab: it eats into the edge by up to two pixels and recolours what is left from the solid ink beside it. It helps; it does not always fix it.

Can I change the ink colour?

Yes. Recolour to one ink turns every stroke one colour — black, blue or any you choose — while keeping each stroke's own soft edge, so it still looks written rather than stamped.

Is my signature sent anywhere?

No. The photo and the signature are opened, combined and saved by code in this tab. Nothing is uploaded or kept.

• Name and date on a photoThe exam-photo label: your name and the date of photograph on a white band, saved under a KB limit.
• Place a PNG on a photoA transparent element starts centred at a restrained share of the frame, ready to size and position.
• Put text on a photoA text layer is on the photo when it opens: words, face, size and a backing that keeps them readable.
• Pale edges on cut-outsWhere the fringe round a transparent PNG comes from, and what Decontaminate and an outline can repair.