How to Sign a PDF on iOS or macOS

Bring your signature workflow into the 23rd century.

by Colter Reed
2:07 read (647 words)
Use a digital signature to streamline workflow.
by Colter Reed
2:07 read (647 words)
Use a digital signature to streamline workflow.

On Star Trek, when a yeoman needed Kirk’s signature, they would hand him a tablet and stylus. Kirk would sign the document digitally and hand it back. That’s a good baseline for a paperless workflow.

A hundred years later, when Picard needed to sign a document, the process had been streamlined to just a thumbprint. Someone would hand him a PADD (it stands for Personal Access Display Device, and I like to think the iPad is named after it), he’d glance over it, and then press his thumb to corner of the screen. A biometric sensor would authenticate the captain and flag the report or request as approved.

Recently, I had to sign a bunch of documents with someone in another city. A bunch of documents. Most of the documents were through DocuSign; those signatures were painless clicks. Not quite the Next Generation experience of providing a thumbprint, but not bad for early–21st century technology. Pretty good, in fact. They even have an iPad app.

A few of the documents couldn’t be done through DocuSign because they required an ink signature. Our instructions for those documents were to print them out, sign them with a pen, and scan them so we could return them digitally.

Admittedly, ink is a 23rd-century technology—23rd century B.C.. The pen itself is a little more modern. But this is the 21st century (A.D.). We can do better than a print-sign-scan workflow that heralds back to the days of faxing. That’s a 19th-century experience. (Seriously—fax technology was developed in 1843. Who knew?)

So you’ve got a document that needs your signature on it. How can you sign it without resorting to faxing?

On iOS, it’s easy. Most apps that let you annotate a PDF will be able to handle this. I recommend PDF Expert by Readdle. Grab an Apple Pencil (or your finger), start editing, and sign away. If you use Spark, also by Readdle, you can seamlessly receive a document over email, sign it in PDF Expert, and send it back.

On macOS, you have Preview. Preview lets you insert a realistic signature into any PDF document. Go to the Tools menu, then select Annotate > Signature. To get started, you’ll need to select Manage Signatures… and Preview will walk you through the process of capturing your signature using the trackpad or signing on a piece of paper and holding it up to the camera.

Once you have captured your signature, you can select your signature from that same menu to insert it into the current document. Position it where you need it, resize it so it fits just right, and even change the color of ink you’re using in your digital pen.

By adding a digital signature to the document, you not only save yourself the time to get to a printer and the hassle of scanning it back into a PDF, but you get better results. The final PDF is just as crisp as the original. No scanning artifacts, no background gradients, no enormous files.

Using an iPad to affix your signature is basically the 23rd-century workflow that Kirk used. You’re living the future! It won’t be long before we have the 24th-century workflow that Picard used, but we’re not quite there yet.

Question: What’s your favorite app for viewing and annotating PDFs? Share your thoughts in the comments, on Twitter, LinkedIn, or Facebook.