Run your assembled PDF through Acrobat Distiller to reduce its file size. In Acrobat 6, try PDF Optimizer.
You started with two or three PDFs, combined them, and then cropped them. Before going any further, consider running your assembled PDF through Distiller. This refrying can reduce duplicate resources and ensures that your PDF is optimized for online reading. It also gives you a chance to improve your PDF's compatibility with older versions of Acrobat and Reader. In Acrobat 6, you can conveniently refry a PDF without Distiller by using the PDF Optimizer feature. Even so, distilling a PDF can yield better results than the PDF Optimizer can.
Refrying traditionally has been done with a simple hack, reprinting the PDF out to Distiller, which creates a new PDF file:
Save your PDF in Acrobat using the File Save As . . . function. Acrobat will consolidate its resources as much as it can. Acrobat 6 does this more aggressively than Acrobat 5 does.
Open the Acrobat Print dialog (File Print . . . ) and select the Adobe PDF printer (Acrobat 6) or the Distiller printer (Acrobat 5).
Set the Distiller profile by selecting Properties Adobe PDF Settings and adjusting the Default Settings (Acrobat 6) or Conversion Settings (Acrobat 5) drop-down box. For online distribution, consider these profiles: eBook, Standard, Screen, or Smallest File Size.
If you cropped your PDF, you should set the Print page size to match your PDF page size. In the Acrobat 6 Print dialog, adjust Properties Adobe PDF Settings Adobe PDF Page Size to fit your page. Use the Add Custom Page . . . button if you can't find your page size among the current options. In the Acrobat 5 Print dialog, adjust Properties Layout tab Advanced . . . Paper Size to fit your page. Select PostScript Custom Page Size if you can't find your page size among the current options.
Print to Distiller. Do not overwrite your original PDF.
Review the resulting PDF. Is its file size smaller? Is its fidelity acceptable?
Reapply page cropping as needed. You might need to rotate some pages.
To restore bookmarks and other features, see [Hack #61] .
PDF Optimizer (Advanced PDF Optimizer . . . ) performs this service much more conveniently. Its settings resemble Distiller's, and they enable you to downsample images, remove embedded fonts, or remove unwanted PDF features. You can also change the PDF compatibility to Acrobat 5. Click OK and it will create a new PDF for you. Compare this new PDF with the original and decide whether to keep it or try again. The best time to use the PDF Optimizer is just before you put the PDF online.
The best time to refry a PDF using Distiller (as opposed to the PDF Optimizer) is after you have assembled it, but before you have added any PDF features. Here is the sequence I typically use when preparing a PDF for online distribution:
Assemble the original PDF pages and Save As . . . to a new PDF.
If page sizes are wildly irregular, crop them [Hack #59] .
Refry the original PDF document and compare the resulting refried PDF to the original. Adjust Distiller settings [Hack #42] as necessary and choose the best results.
Crop and rotate the refried PDF pages as needed.
If the original document had bookmarks or other PDF features, copy them back to the refried PDF [Hack #61] .
Add PDF features [Hack #63] or finishing touches [Hack #62] .
Save again using Save As . . . to compact the PDF. In Acrobat 6, save the final PDF by selecting File Reduce File Size . . . and set the compatibility to Acrobat 5.