Thursday, 10 December 2009

How to crop unwanted margins from PDF scans, free

This post shows how to get rid of black margins (or margins showing page edges etc) before printing out PDFs, thus saving money on printer ink and being more environmentally friendly.

Say you scan a few pages from a book to PDF and you want to print it out. Too much black ink is often wasted when printing PDFs produced by scanning pages from books or magazines where the page is smaller than the scanning area, because the space where the scanning area is bigger than the book or journal page shows up in the scan as dark margins, as in the pic below - and similarly when you're scanning photocopies of pages from books or journals. (All copying & scanning done within fair use or fair dealing limits, of course!)

But you can eliminate unnecessarily ink-wasting black margins from your PDFs simply by cropping the margins from the PDF, saving the cropped version, and then printing out the cropped file instead.

A very good free tool for cropping PDFs is PDFill PDF Tools (free for private use).

How to crop black margins from PDFs using PDF Tools

  1. Preparation - open up the PDF file which you want to crop, e.g. in the usual Acrobat Reader. Usually the unwanted dark margins will be on 2 sides of the page. Here is an example (taken from The Future of the Internet by the brilliant Jonathan Zittrain as he's a very nice man who I'm pretty sure won't mind my using 1 page from his book to illustrate this):

  2. Make a note of which sides those extra black margins are on, e.g. top and left, and estimate how much of the page they're taking up and therefore how much needs cropping. E.g. in the UK, with an A4 page size scan, in the above example it might be 0.5" left and 2 or 3" bottom, i.e. you want to remove 0.5" from the left margin and say 3" from the bottom margin. Maybe even about 1.5" from the right margin too, in this case.
  3. If the PDF document is several pages long, as it often is, make sure you page through it quickly to figure out what measurements (e.g. 0.9"?) would deal with most of the bits you want to cut out, while leaving the substantive text untouched. It won't be perfect but at least you should be able to get most of it. If you don't check this there's a danger you might cut out too much.
  4. Download PDFill PDFTools and install it if you haven't already.
  5. Launch PDF Tools.
  6. Click button 4, "Rotate or Crop PDF Pages":

  7. In the file chooser that comes up, select the PDF file you want to crop.
  8. Make sure you tick to select "All pages" on the right, otherwise it will only crop the first page. (That's why in 3. above I said skim through it to work out what measurements would be the best for all pages.)

  9. Then, in the "Crop Box" section on the left, fill in how much should be cropped for each margin, i.e. how much you want to take off from the top margin, left side, right side or bottom margin. It defaults to inches (") as you can see. So for the example in 1. above I'd try - Left Margin 0.5", Right Margin 1.5", Bottom Margin 3" and leave Top Margin alone as 0".
  10. Then click the Save As button and - this is important! - give the file a new name, not the same name as the original PDF document. E.g. you could call it say "scancropped1.pdf". And click Save.
  11. Open your newly created PDF, e.g. scancropped1.pdf, in Acrobat Reader (or Foxit or other PDF reader of your choice) and you'll see the margins are gone. Page through it to make sure you've cropped the margins you didn't want but not lost any important page content. And just print it out from there. This is what my example looked like after I put in the measurements listed in step 9 above - not bad guessing on my part:

  12. If during your skim through you notice it's cropped too much, or too little, no problem. Just start again from step 7 above, but this time try slightly different measurements for how much to chop off, then save the file as a new file (or even overwrite scancropped1.pdf if that was really unusable, but again don't overwrite the original file). Just keep trying till you get it the way you want - with experience it only takes me 1 or 2 goes, and then voila I can print the PDF scan without the dark margins. In the example I showed above, I could even start with the newly saved cropped PDF file, take a bit off the top margin say 0.5", and I'd be there.

And that's it. The PDF Tools suite has some other useful tools for working with or tweaking PDF files, including converting images to PDF and vice versa - just have a play and see (if you hover over a button more info is given, and the Help is good).


PDF-puzzled said...

Thank you, very useful!

Anonymous said...

Did anyone try printing?
At least with foxit, when you print the new file, it draws the full page, like if you were printing the original file.
In the printing preview it looks OK but the printer gets the full image, it doesn't consider the new border parameters.

Anonymous said...

1 click crop tool:

Anonymous said...

Thank you very much!

Very clear, very useful!