Many pdf’s comes with big white borders. This becomes a problem when reading pdf’s on ebook readers since the borders takes up a lot of space on an already small and challenged reading area. Or when one wants to save some trees when printing the document. Well, there’s a solution for this in macosx.
Open the pdf in Preview.
Open the sidebar: Preview Menu –> View –> Sidebar
Choose Thumbnail view: Preview Sidebar –> On the bottom left there is an icon, click and choose Thumbnails. Ensure that you have one of the pages selected/marked.
Select all the pages: Preview Menu –> Edit –> Select All
Choose the Select Tool: Preview Menu –> Tools –> Select Tool
Now you can mark the area of the page that you want to keep. Since you previously selected all the pages, the changes will occur on all the pages.
To remove the unmarked area: Preview Menu –> Tools –> Crop.
Now you can save the document.
This worked as a charm for me and the pdf’s ended up looking good in my iliad, though the font size is still a bit small (but still readable) in most cases.