Can’t find a way to set a seal image beneath text or table of document.
By the way, I’m programming with C#.

I have tried to use functions like PdfPadesSigner.SignWithBaselineBProfile or PdfSigner.SignDetached, but all of them attach a solid image on the text, so that other users can’t recognize what text covered by that seal’s image.
This confused me a long time. I know it is possible to change opacity of signature image, but I don’t want to change that. I wonder is there a way to just let that image stamped beneath document’s texts.