Unnecessarily large file PDF sizes when creating them from Word

Question

Using Acrobat XI Pro, if I create a PDF from Word - whether I do so by using the Acrobat Add-in for Word or by using the Adobe PDF print driver - I get unnecessarily large PDF file sizes even though in both cases the print quality is set to Standard.

If I then open the PDF in Acrobat and print the PDF I've just created to a new PDF file - again with the the print quality set to Standard, the resulting PDF file size is dramatically smaller, but with no noticable reduction in quality.

To give a specific example, I want to create PDF files from a couple of Word documents containing text plus a lot of graphics.

In the case of File 1:

the original Word file is 22MB;
the PDF I get from it is around 13MB - regardless of whether I create it by Acrobat Add-in for Word or by using the Adobe PDF print driver
The PDF I get if I open the resulting PDF in Acrobat and print it to a new PDF file using the Adobe PDF print driver is only 5.5MB.

In the case of File 2:

the original Word file is 28MB;
the PDF I get from it is around 23MB - regardless of whether I create it by Acrobat Add-in for Word or by using the Adobe PDF print driver
The PDF I get if I open the resulting PDF in Acrobat and print it to a new PDF file using the Adobe PDF print driver is only 8.5MB.

This makes no sense to me, given that the Adobe PDF print driver or Add-in is using the same Standard print quality setting in all the above cases. Why does it produce a dramatically larger file size when creating the PDF from a Word file and a dramatically smaller file size (with no discernable drop in quality) when creating a PDF from an existing PDF that was previously created from the same Word file?

The reason this matters is that I want the smaller file sizes as there is no noticable loss in quality and I want people to be able to view the PDF on the web even if they have a slow internet connection - but I want to create the PDF using the Acrobat Add-in for Word, so that the Word headings will be automatically converted to bookmarks in the PDF, Word hyperlinks will be automatically converted to PDF hyperlinks, etc.

Can anyone explain the above strange results, and is there any workaround that would allow me to have my automatically created bookmarks etc. but without the excessive file size?

Dave

Dov Isaacs · Accepted Answer

Hi Dave,

Thanks for providing the links to your source Word files and the resultant PDF files.

It is very clear what is going on here, just by examining the first Word file, its exported PDF, and the “refried” PDF obtained by printing the PDF file to the Adobe PDF PostScript printer driver instance.

As noted by Test_Screen_Name your initial PDF file created by Acrobat's PDFMaker from Word is primarily image data as shown by the Audit Space Usage function from the PDF Optimization function:

Other than images, all other aspects of the PDF file are effectively negligible. With Acrobat 11 (which you used), the Standard joboptions compress images with 150/225 dpi medium quality, lossy JPEG compression. The image quality is adequate for amateur printing.

When you subsequently “refried” the PDF file, you ended up with a new PDF file in which again the major percentage of the much smaller PDF file was again the image data:

Why is the image data now less than half of that you originally had? Simple! JPEG compression is lossy and especially when “medium quality” is specified. Furthermore, recompressing existing JPEG-compressed images, even with the same settings, incurs further lossiness. In other words, cascading lossy compression can yield exceptional image quality loss. You may not notice the difference in quality, but we do!

The bottom line is that the PDF file you initially got by PDFMaker was absolutely not “unnecessarily large” for the image quality you received. If you want/need a significantly smaller PDF file and are willing to accept significantly degraded image quality, change the joboptions from those in Standard to use low quality JPEG compression as opposed to medium quality JPEG compression. However, such PDF files will not yield anything approaching professional quality display and/or print. (There are tradeoffs in life, correct?)

You should be aware that due to user complaints about image and overall image quality in PDF files created by Acrobat, about a year and a half ago we changed the settings for the Standard joboptions for Acrobat DC and Acrobat 2017 to embed all fonts (not embedding common so-called “system” or “common” fonts is a recipe for disaster for those who receive such PDF files) and to use less downsampling and higher quality image compression:

One should note that virtually all high-end mobile devices have screen resolutions in the range of 300dpi as do newer 4K computer monitors and even the screens on high-end laptop computers. The old canard that 72dpi or 150dpi was adequate for screen display has been consigned to the dustbin of history. In fact, the resolution requirements for screen display are no longer less stringent than those for print!

Dov Isaacs · Answer

You cannot make generalizations as to what are or aren't unnecessarily large file PDF sizes when creating them from Word. We would need to see samples of the original Word documents and resultatnt PDF files to ascertain whether in fact the results are “unnecessarily large” or not.

You cannot legislate PDF file sizes. PDF file sizes depend on the original content and exactly what that content consists of plus whatever joboptions you've chosen for PDF creation.

Provide samples and maybe we can give you a solution.

BTW, contrary to the previous posting, Acrobat DC is absolutely not the solution here!

Sign up

To post, reply, or follow discussions, please sign in with your Adobe ID.

Sign in to Adobe Community

To post, reply, or follow discussions, please sign in with your Adobe ID.

Scanning file for viruses.

This file cannot be downloaded