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I’m all in favor of paper conservation and keeping our collective environmental footprint in check, so naturally I understand why some people feel obliged to print two ‘pages’ side by side on one physical page; a phenomenon I like to call ‘double-print’.
But even though PDF’s are often destined for print, the fact is they are just as often distributed digitally. More often than not, this means you end up with a double-paged document on your computer, or your tablet. When you reach this point, you’re no longer minimizing your digital footprint. It’s not smart or economical, either. It’s just unwieldy.
What This Will Accomplish
This article will show you how to split your double-printed PDF pages on Mac OS X, making them more readable and portable. Most importantly, you’ll be able to keep in-line text, formatting and images, using only free tools.
The Tools Of The Trade
There are two prerequisite applications for this tutorial. The first, Preview, should already be present on our Mac.
We’ll also need a nifty tool called PDF Sam. You can download it for free from the website. Once you’ve installed it on your Mac, we’re good to go.
1. Duplicate & Crop
In this first step, we’ll be separating what will eventually be our odd and even numbered pages. Before you do anything else, duplicate the PDF document. You can call one of the documents ‘even-pages’ and the other ‘odd-pages’.
Open the ‘odd-pages’ document, and select the portion of the page you’d like to separate. Use the zoom function and the selection handles to optimize your selection, and make sure not to select any abundant whitespace.
Open the thumbnail tray from View -> Thumbnails, click on one of the pages’ thumbnails, and select all with cmd + a, or Edit -> Select All. Finally, press cmd + k, or use Tools -> Crop to crop the entire PDF around your selection, and save the file.
Now, open the ‘even-pages’ file, and go through the same steps. However, this time crop around the other section of the page. In the end you should have two PDF files; one with the odd numbered pages, and the other with the even numbered pages of our future document.
2. Merge Odd & Even Pages
Fire up PDF Sam. In the left sidebar of the application, select ‘Alternate Mix‘ in the list of plugins. Next, add the two PDF’s you created in the previous step to the application, with the ‘odd-pages’ PDF first, followed by the ‘even-pages’. Make sure the ‘Mix options‘ are both left unchecked, select a target output file, and hit run.
This step will merge the two PDF’s, alternating between pages of the two input files. The end result is a single PDF with the double-printed portions neatly separated.
3. Make The Crop Permanent (Optional)
Because of the way cropping PDF’s works in Preview and a lot of similar pages, the content you cropped away is not really gone. Rather, it’s just out of sight beyond the document’s borders. In most cases, you can use the document you just generated as is. However, documents that are cropped this way contain a lot of duplicated content, so can be double the file size.
Using a PDF printer is the easiest way to get rid of this duplicated content, radically decrease the document file size and make the crop permanent.
With your file open in Preview, go to File -> Print. A third-party PDF printer application may give you the luxury of dynamic page sizes, but we’ll have to create a paper size that matches our document. To do this, select Paper Size -> Manage Custom Sizes, and create a new profile. For presentation slides, the profile visible in the above screenshot (with a 4:3 aspect ratio) works like a charm. Make sure to empty all the ‘non-printable area’ boxes.
Finally, with your custom paper size added and selected, go to PDF -> Save as PDF… in the bottom left of the print dialog.
Did you experience any problems with this tutorial? Do you know any other worthwhile workarounds? Let us know in the article comments.