When you receive a digital PDF contract via email, the traditional method of signing it is incredibly frustrating: you must print the document, sign it with a physical pen, scan the paper back into your computer, and email the resulting massive image file back to the sender. This completely breaks the digital workflow and degrades the quality of the document. If you use a Mac, you can skip the printer entirely. The built-in macOS Preview application allows you to create a high-quality, legally binding digital signature and stamp it directly onto any PDF.
How to Create a Digital Signature
Before you can sign a document, you must create a master signature profile. You only have to do this once; your Mac will securely save it for future use.
- Double-click the PDF file to open it in Preview.
- Click the Show Markup Toolbar button (it looks like a small pencil tip inside a circle) located in the top-right corner.
- Click the Sign button (it looks like a small cursive signature).
- From the drop-down menu, click Create Signature.
Preview offers three distinct ways to capture your signature:
- Trackpad: Click this option, and your Mac’s trackpad transforms into a giant digital canvas. Use your finger (or a stylus) to physically write your signature on the glass trackpad. Press any key when finished.
- Camera (Best Quality): Sign your name with a thick black pen on a blank piece of white printer paper. Select the Camera option and hold the paper up to your Mac’s webcam. The AI will instantly detect the ink, strip away the paper background, and generate a flawless digital vector image of your signature.
- iPhone/iPad: If you are signed into the same iCloud account on your iOS devices, this option pushes a blank canvas to your iPhone or iPad screen, allowing you to use your finger or an Apple Pencil to sign comfortably on the touchscreen.
How to Sign the PDF Document
Once you have saved a signature profile, applying it is practically instantaneous.
- With the PDF open in Preview, click the Sign button on the Markup Toolbar again.
- Your saved signature will appear in a drop-down list. Click it once.
- The signature will instantly appear in the exact center of the PDF page.
- Click and drag the signature to the correct signature line on the contract. You can also click the blue handles on the corners of the signature box to scale it up or down so it perfectly fits the allotted space.
Once you are satisfied with the placement, press Command + S to permanently flatten and save the PDF file, ready to be emailed back to the sender.