Exporting signatures from Preview

Recently I was on the road and a document needed my signature. Preview makes signing PDFs easy but unfortunately I was working with a different format.

Writing and scanning instruments were unavailable to me; I just needed to ‘extract’ a signature saved in Preview. The solution wasn't exactly intuitive, so I'll share it here.

Open Preview's preferences and head to the Signatures tab. Highlight the signature you want and copy with ⌘C.

* Follow Apple's lead on signature security. Take necessary precautions and don't leave it lying around!

* Follow Apple's lead on signature security. Take necessary precautions and don't leave it lying around!

Now invoke a New from Clipboard with ⌘N. The result is a transparent image with the signature. Save this (e.g. PNG with alpha) and use as you wish.*

Not my  actual  signature…

Not my actual signature…

I was hoping to script this (script all the things!) but hit a stumbling block. Preview stores signatures in:

The array of data elements are presumably the signatures. They're encrypted — a password related to this can be found in the login keychain.

Unfortunately, even with this information, I've not been able to decrypt the data to a useful form. If anyone has any pointers, let me know below.