If you have experience on publishing research papers, you may know about submitting a agreement on copyright to a publisher. Usually, you need to print a copyright form out, write your signature, make a photocopy of it, and finally send a PDF of TIFF to the publisher by e-mail or upload it to a publisher's web. However, it's quite annoying procedure and the quality of a scanned copy of the form is not good. Moreover, you need a printer machine and a scanner to do this. On the other hand, we do not send the printed one to the publisher in these days and thus it's a waste of a paper because it is just used for create a photocopy.
If you are a MAC user, there is a simple and elegant way to do it without any additional hardware, i.e., printers and scanners.
The 'Preview' application, which is a default application for viewing images and PDFs on MAC OS X, provides a function that allows you to insert your signature in a PDF file.
You can see how it works from: Help->Search.
Type 'signature' and you'll see appropriate menus and help items.
If you click the inverted triangle , you will see a sub-menu, saying 'Create Signature from...'. Just select it.
Then, you'll see a video stream captured from your machine's FaceTime camera.
Following the guideline in right, first write your signature on a white paper. Avoid using a pen with a very thin tip. If lines of your signature are too thin, signature detection will fail.
Then, put your signature in front of the camera. Make some overlap between your signature and the blue line on a screen. The machine detects your signature automatically and shows it as below. If the detected signature is good enough, press Accept. Your signature is saved to the Preview app.
To add the created signature to a PDF, select appropriate signature from the sub-menu of the signature tool and put the mouse cursor (it becomes cross) on a right location of the PDF.
If there is a line, you'll see a blue guideline. If you click at the location, your signature will be inserted there.
Here is a screenshot of inserted signatures !!