I think that with Paperport you will have an opaque one since you have to create a bitmap file.
Transparent background sounds interesting. How do could you do it?
There are two graphic file formats that support transparency:
1) the .gif - Compuserve
2) the .png
To create a transparent signature file, I would advise using a .gif.
First Scan your signature, signed in black ink, on a white sheet of paper. Scan as a black and white document.
In your photo editing software create a NEW image with a transparent gif format.
Open your scanned signature in the Image Editor
Copy your signarture and paste it into the new transparent file you created.
Select white as the "Transparent Color"
Only the signature should remain. Save the file and you're done.
