1. Users need to sign your name on a completely blank piece of paper.

2. Open the PDF file we want to hand-sign in the Mac, click the preview function on the menu bar, and then select the "Preferences" option.

3. Then select the "Signature" option in the preference interface, and then click "Create Signature".

4. The camera interface will open. At this point, aim the newly signed white paper at your camera, and then adjust the position of the paper according to the signature preview interface on the right. It is worth noting that it has a blue line on the camera display interface. As shown in the figure below, the user's signature must be above this blue baseline. When you feel the position is suitable in the signature preview, you can click Accept.

5. When we enter the PDF interface, we click "Edit" in the menu bar, and then select "Signature" in the options. Select your signature at this time, and then drag the cursor directly to the position where you want to sign.

If the features in the preview are not what you want, you may find them in another PDF editor, which is not built into macOS. We have a list of free PDF editors, most of which can run on Mac.

Another way to edit a PDF in macOS is to use an online PDF editor. The same list linked above are some of these service types. The way they work is to upload the PDF to an editing website, where you can edit it and download it back to your computer.