Adding a signature in Preview for OS X

Signing PDFs With Mac OS X: A Beginner’s Guide

Preview is OS X’s default application for viewing PDF files. If you scan a document, it will probably turn up as a PDF file, so this is the application used most often for things scanned into the system.

This Preview app has an awesome and almost hidden function – it allows you to scan a signature with your Mac’s camera, then store that signature and easily add it to any PDF file. This is handy for any user, but for those users who can’t easily manage a pen to sign physical documents it’s a really useful accessibility function too.

Setting Up

Setting up your signature is a touch fiddly, but only needs to be done once so it’s worth the effort.

First, sign your name on a piece of blank paper using a black pen. It doesn’t matter how large or small your signature is, you can change the size later, but if you sign it large you’ll need to use a thick black pen. Here’s mine:

Here's my signature before capturing.
Here’s my signature before capturing.

Now find a PDF file that needs your signature and open it up in Preview. I used a birthday card template from Pages because birthday cards are a nice place to put signatures …

Here's my card, ready for a signature
Here’s my card, ready for a signature

Now you need to open the menu and you’ll see why I said this function is hidden – the menu you want is Tools > Annotate > Signature > Create Signature From… as this picture shows:

OS X Preview Menu Tools > Annotate > Signature > Create Signature
This is the deeply buried menu for creating a signature.

Mine says “Create Signature From aGent V5 Full HD” because that’s the camera I have. If you have a Mac with a built-in camera it will probably say “Create Signature From FaceTime HD Camera” but whatever webcam shows up in that menu is fine to use.

Now hold your signature sheet up to the camera – the blue line is there to help you get it straight, you don’t need to have the letters sitting exactly on the line:

Signature being correctly recognised.
Adjusting the lighting and exact position of the page let me capture it exactly.

If your capture looks like this, your signature is written in a pen that’s too pale, or the lines are too thin for the camera to pick up, or the page is out of focus:

Recognised signature has gaps in the lines.
When I draw my large signature with a fine pen, Preview doesn’t recognise it.

Other things that can affect the capture are the light in the room, the texture of the paper you wrote on, and how stable the image is relative to the camera – if you aren’t happy with what you got, fiddle around until it works right. Once it’s done you can re-use it forever, so it’s worth a bit of effort.

Click “Accept” when you’re happy with the captured signature.

Adding Your First Signature

Now your mouse pointer will look like a vertical cross symbol – click on the PDF where you want to insert the signature, then drag the dots until it’s the size you want. Bingo – one signed birthday card:

Signed cards are much more personal.
Signed cards are much more personal.

Signing More Documents

Next time you want to add a signature it’s much easier – just click on the edit toolbar toggle or select View > Show Edit Toolbar from the menu, then click on the signature glyph in the edit toolbar.

Graphical version of instructions.
Once your signature is set up, it’s as easy as 1-2-3 to add it to another document.

Now click on your PDF to add and resize your signature as before and that’s all!

– Ricky

Leave a Reply

Your comment may be held up by our moderation or anti-spam software: please be patient if your comment does not immediately appear. You can include some HTML in comments, but including links or web addresses makes it more likely your comment will be delayed by moderation. Please stick to the comment policy.