Appearance

A visible signature is a widget annotation with its own appearance stream. UniPDF builds it one of two ways. annotator.NewSignatureField draws a list of annotator.SignatureLine with annotator.SignatureFieldOpts, and nothing in it is read back from the signature, so the box shows whatever you put there. Appearance field covers position, font, colors and borders, and Image appearance adds a scanned signature image and a watermark. PdfAppender.SignWithAppearance draws the box from the signature’s own name, date, reason and location instead; see Generated appearance.

The examples are in signatures/appearance.