digital signature size

[murrays]

In order to apply a signature to forms I have created a graphic of the signature, imported it into Acrobat and saved it as a .pdf file. I have established this .pdf file in the Configure Signature Appearance box. When I attach this file as a signature on the form, the file appears very small. I have increased the size of the graphic hoping that would make the file larger but it doesn't change the size. I read an article that stated that Self-Sign Security crops and scales the picture to fit in the signature field. This picture looks much smaller than the field defined. What do I need to do to make the graphic large enough so that it is legible?