With e-filing many lawyers are now "signing" pleadings without physically signing them. We’re going to see more of that in the future. So Adobe’s Rick Borstein has a nice post on how to build a transparent signature stamp in Adobe Acrobat, The signature with transparent background is much more appealing on a document than one with a white background. He also adds a reminder that you can "add simple usage restriction security to prevent copying the signature from the document."