Do you mean your hand-written name signature?
Open a blank document in any pixel editor ( Photoshop, etc) transparent background if possible.
Select the Brush tool & a very small brush. Black.
Write your signature using the wacom,
Signature will be Black on transparent,
You can trim the document to just the signature,
Save the file as a PNG type file that you can use as a graphic Logo or watermark.
Also make a signature (or any thing, Logo, etc) into a Photoshop "Brush"-
Write with the Wacom, Black on White background,
Marque select the signature,
Go Menu > Edit > Define Brush Preset.