Update: So many people are looking for this. We have updated this post in 2/2017 to reflect how its done in High Sierra. Go Here to check it out.Among the many great features in Lion is the camera-scanned signature function for PDF documents — You most likely already know how to get your signature into the computer; Open the Preview application > Choose Preferences, click Signatures, and then click Create Signature. Hold a white piece of paper of your signature in black ink in front of the the camera in your computer aligning the signature to the blue guide line — Once you have the signature on the line, level and centered, there’s no need to continue holding the paper up. Take the paper away and you’ll see it continue to be refined via software. Ok now its in.
Add your signature to PDF documents using Preview.app’s Annotations toolbar. If its not visible you’ll have to show Annotations from the menu. One thing you can’t do is drag this placed sig. to the desktop or another application – it is locked to the page, something the engineers put thought into because leaving the signature file unlocked opens a real security issue with someone being able to copy it off your computer.
But thankfully, there is a technique to using your scanned signature in other applications. Here is how to get your signature you created in Preview.app into other Apple programs like Pages.app and Mail.app. Do this: Once the signature is saved in Preview.app, access it through Preview > Preferences > Signatures pane. You’ll see visuals of the signature or multiple signatures you created and last times they were used.
Try as you might you won’t be able to drag the signature out of the box. Instead select the signature from the signature manager window and do a Copy, Apple-C. Now its on the clipboard. Then switch to a Pages file where you have a document open needing your signature. Hit Paste, Apple-V to paste the signature as a graphic that can be moved or resized. Be aware of the floating vs. inline features of Pages. Here’s how that works. If the cursor is positioned in a line of text, the pasted graphic is locked to the cursor position. To create a floating graphic, deselect the text tool and then paste. Now the graphic is “Floating” so you can move it freely around the page.
To add that signature as a email signature you can select when composing new mail, get into your Mail preferences > signatures and paste the graphic there.
C Denver Macintosh