How to Sign a PDF Document on a Mac

Starting with macOS Lion (10.7), Apple introduced a smart method to add a written signature to a PDF document. But the procedure has changed over the years. Here’s how to do it today. (High Sierra and later.) You are using the macOS sample application.

In his 2013 article here at TMO, Sandro Cuccio set the starting point.

Why would you want to do this? Perhaps the most important reason is that legal documents signed in PDF format are increasingly used and accepted. Fortunately, the outdated fax machine goes through the floppy disk drive, audio modem and mouse. Actually any company that still needs faxed documents – well, I don’t give them my company. The wind of time has disintegrated my fax machine, and going out to get faxes is embarrassing.

Apple comes to the rescue.

Steps to add a signature

1. First, grab a piece of printer paper and write the signature you want in black ink all by yourself – be sure to keep it in a straight line without actually using a helpline. Like that.

2. Starting with macOS High Sierra (10.13) and still in Catalina (10.15), Apple has added a formatting toolbar to the Preview application. This is what’s new. To access it, click on the icon indicated here:

3. In the now visible annotation toolbar, click the “Sign” icon. Like that:

You will see a pop-up window with all the signatures you already have in the file.

If the one you want is not there, click on “Create signature”. A camera window opens. Hold the piece of paper you made in step 1 in front of the camera lens until it is reflected in the monitor window. Like that:

Note: Here you can switch to a trackpad if necessary. (Camera broken.)

As soon as the application detects a suitable signature, which is held above the blue line, it will be saved in your list.

Now repeat step # 3 and select your new signature. It is placed on the document, ready to be moved to where it should be. Drag a corner to resize if necessary. Click anywhere else in the document to remove the format sliders. Like that:

Now click File> Save (or OPT + Save As #..) and you are done with your signed PDF document.

Reference

For more information about the formatting toolbar, see the Apple website “Annotate PDF in Preview on Mac.‘