How to scan and size your signature for exam forms

Signing

• Black or dark blue ink on plain unlined white paper.
• Sign in your normal running hand. Block capitals are rejected by most boards, because a signature has to be reproducible for later verification.
• Keep it inside an area roughly three times as wide as it is tall, matching the 6 cm × 2 cm strip most forms expect.
• Use the same signature you will use on the answer sheet and at document verification. A mismatch there is a far more serious problem than a rejected upload.

Capturing it

Photograph the paper straight-on in daylight, with no shadow from your hand or the phone falling across it. Shooting at an angle skews the strokes and leaves one side of the page darker than the other.

A flatbed scanner is better if you have access to one, but a phone photograph in good light is perfectly acceptable.

Why the file comes out too small

A signature is a few dark strokes on a large field of white. JPEG compresses that extremely efficiently — often to two or three kilobytes, well under the 10 KB minimum most portals set.

Reducing compression cannot help, because lowering quality only ever makes a file smaller. The only way to raise the size is to increase the pixel dimensions, giving the encoder more data to store. A tool that understands the minimum will do this automatically; one that only targets the maximum will hand you a file the portal rejects.