Preview: More Than Just a PDF Viewer

Sometimes we’re prone to overlook the core OS X applications. When people think of PDF editing software what comes to mind; Adobe Acrobat, PDFPen, Skim. But what about Preview? If you think Preview is just the application that pops up when you download a PDF, you’re missing out on a great deal of functionality.

Preview is capable of far more than viewing PDFs and contains basic editing features, quartz filters, the ability to manipulate pages, and draw annotations. This how-to will walk you through a variety of the less well known Preview features, and illustrate what the app is capable of.

Cropping a File

Step 1:

First fire up Preview and open a PDF document. For this example I am using the iPhone User Guide (for those who are curious!). Use the selection tool, located on the main Preview toolbar, to select the area you want to keep. Anything outside of the selection area will be cropped out.

Preview Menu Tools

Preview Menu Tools

When you are done using the selection tool you should get something like this, a selection frame around the portion of the PDF document you would like to keep with the rest of the document grayed out and slated to be cropped.

Selecting Tool

Selecting Tool

Step 2:

After you have selected the area you want to keep, go to the main menu bar and look for Tools > Inspector. If you are more comfortable with keyboard shortcuts just press Command + I instead.

Tools Menu

Tools Menu

Step 3:

Once you have brought up the Inspector navigate over to the Crop and Rotate tab, which looks like a ruler. Once there, you have two cropping options. First you can crop only the current page. This option will crop only the page you have drawn your selection box around but will leave the other pages untouched. The second option will take and crop all of the pages of your document. This is especially handy when you are trying to remove white space and headers in your PDF document to make it more readable on portable devices, or when printing.

Crop and Rotate

Crop and Rotate

Rotating a File

Step 1:

To rotate a PDF we need to go back to the Inspector, either through the keyboard shortcut or menu bar.

Step 2:

Once you have brought up the Inspector navigate over to the Crop and Rotate tab, which looks like a ruler. Look at the bottom on the box and you have two rotation options. As with cropping, you can rotate the current page or you can rotate all the pages in the entire document.

Rearranging, Adding, and Deleting Pages in a Document

Step 1:

Modifying the structure of a PDF document is incredibly simple if you are in the right view. The Preview sidebar has two different views, either showing the table of contents, or a list of thumbnails. When you’re in the table of contents view you will not be able to modify the structure of your PDF document. To switch to thumbnail view, click the button with the downward pointing arrow and make sure you are in thumbnail mode instead of table of contents mode.

Something

Switch to Thumbnail View

You’ll see something similar to this:

The Thumbnail View

The Thumbnail View

I you want to rearrange pages you just need to click and drag; simple right? You can even click and drag pages between multiple PDF documents. If you want to delete a page just go to the Edit menu on the main toolbar and press the Delete Selected Page button or press Command + Delete. You can also insert a blank page from the Edit menu. Once you press the insert blank page button the blank page will be inserted before the page you are currently on or have selected.

The Edit Menu

The Edit Menu

Using Built In Quartz Filters

Preview contains eight built in Quartz Filters. To use the filters go to the File tab on the main toolbar and click the Save As button. Once there, at the bottom of the dialog box, you have a drop down box with a list of eight filters you can use on your PDF documents. You are probably wondering what these filters do:

  • Black & White – This filter removes all color and turns your PDF document black and white. Useful when trying to remove the color to make a document more printer friendly.
  • Blue Tone – This filter gives your document a blue tint.
  • Create Generic PDFX-3 Document – Many newer PDFs have features incompatible with older PDF processors. This filter removes all of these newer features and turns your PDF document into a PDF-X document with maximum compatibility with other processors and readers.
  • Gray Tone – Gray tone is similar to the black and white filter but turns the document into shades of gray rather than strictly black and white.
  • Lightness Decrease – This filter is used to decrease the lightness of your PDF.
  • Lightness Increase – As you’d expect, used to increase the lightness of your PDF.
  • Reduce File Size – This filter reduces the quality and size of the images in the document to reduce the overall file size. This is very handy if you are trying to reduce a PDF ‘s size to reduce upload and download times.
  • Sepia Tone – This filter gives your document a red/aged tint.
Save As Dialog

Save As Dialog

Once you have selected which filter you’d like to apply, choose where you want to save the PDF to and press the save button.

Annotations

This feature is incredibly useful for marking important areas, as you would if using a traditional pen and paper. Four annotation options allow you to add an oval, rectangle, note, or link.

Annotations Menu

Annotations Menu

Adding an oval and adding a rectangle do not allow you to add any text but provide a frame that you can use to remind yourself and others that the text or graphic inside the frame is important. Once you select either the oval or the rectangle you just draw the shape around what you want to be highlighted, similar to the selection frame earlier in this article. You should get something similar to this if you are successful:

Annotation Example

Annotation Example

The add note function is similar to a footnote in a book or paper. You place a speech bubble near the text you want to note and a note appears on the right hand side of the page where you can add text that you can refer to later. The placement of the note on the right hand side will line up with the speech bubble to help you keep track of which note is referring to which speech bubble.

Adding Notes

Adding Notes

The last function of annotation submenu is the ability to add a link. Did you ever notice how on some PDF documents the table of contents was not just for show? You could click on chapter two and it would magically take you to chapter two in that document. Well you can do that as well with Preview. Once you click on the Add Link button you will get a shaded rectangle tool similar to a section rectangle. All you need to do is draw a box around where you would like a link.

Adding Links

Adding Links

When Preview brings up the shaded rectangle link tool it will also popup the annotation tab on the Inspector. Here you have two options; you can either point the link to a page within the current PDF document, or you can have the link point to a URL.

If you choose to have the link point to a page within the current PDF document you need to go to the page that you want the link to point to and press the set destination button while on that page.

Linking Within a PDF

Linking Within a PDF

If you want to have the link go to a URL use the dropdown button under attributes and change it from Link within PDF to URL.

External Links

External Links

Conclusion

There is a decent range of functionality in Preview which isn’t immediately obvious at first glance. For a free tool within OS X, it’s actually fairly proficient at handling images/PDFs and offering basic editing operations. Don’t write it off as a mere viewer, and I hope you’ve discovered a new way to manipulate PDFs.

If you’d like to highlight any additional features present in Preview, please do let us know in the comments!