PDF file sizes.
PDF file sizes.
I too get files of extremely varied quality. The size of the output file is a balanced result of number of pages, how many fonts are embedded, (fully or subset) how many graphical elements are in the file, (pictures, boxes, banners) etc.
The resolution of those graphics is probably the key factor in the final size. Anything under 150 dpi and they start to look really bad. Bt higher resolutions take up more space. How many pages are we talking about?
It may be that some your supplied files are created wrongly, where every page is saved as a graphic. This is a common error (Print As Image) and results in large files for relativley small page counts. Sometimes the same effect is created by down versioning the output file. (Make compatible with .. e.g Acro.Ver 5) These can be optimized or shrunk to a smaller size but you'll be very unhappy with the results as the resolution must be brought down. On a text page saved as a graphic 600 dpi will usually be acceptable but not great. And you may somtimes get an unwanted background effect too. You may have to educate your clients how to produce the file correctly. I wrote a simple one page guide to producing a pdf correctly, which my sales people can send to their clients.
Those files that seem to get bigger when optimized are probably comming from Acrobat 9 which supports advanced layering and layout "features" which reduce the file size. This is great for sharing files and on screen or web use, BUT when you "print" these, they are flattened (optimized) in the process, growing larger. If you optimize before printing (as most do) you can expect these to be larger than the originals. I have found no way around this, but usually the increase is not huge.
My usual procedure is to re-process every pdf I get. That is, with my version 8 Acrobat, I have a "Printer" (Print to PDF) setup at my optimum settings. This automatically takes care of 95% of my issues. In version 9, printing to a new pdf is NOT supported so normal optimization is needed, but at present, this level of PDF file is relatively rare.
I hope this has been of some help to you.
Since I also create pdfs, in my standard settings I include, Embed all fonts, subset under 10%. For my laser print, I use down sample B&W images to 600 dpi, Color images to 300 dpi. Leave the text and line settings at 1200 dpi.