3 Replies Latest reply on Jun 27, 2012 5:55 AM by Bill@VT

    Controlling file size when using Preflight?


      Our company takes PDFs from magazine publishers and uses proprietary software to convert to PDFs to SWF, PNG and JPG for different Web delivery channels. The problem I run into is the occasional page where the graphic designer used many layers, and I have to take the PDF they gave us and do custom Preflight work to yield a PDF that won't cause our software to choke. Typically I'll choose to output a version as PDF/X-1a. This will do some cleanup like Remove Artbox, Flatten transparency, Discard form objects, Discard external cross references, Remove alternate images, Remove document structure compression, Recompress LZW as ZIP, etc.  Despite action names that suggest Acrobat is taking out unnecessary things, it's not unusual for file size to go from 220 KB to 7.4 MB. That's a problem because even though this creates a PDF that is more likely to look normal after conversion to images, those images may be so large that download is slow. If I take that PDF I just made and run the Fixup Flatten transparency (high resolution), file size will drop to about 5.9 MB (these sizes are a test I ran for this post).


      My first question concerns the PDF/X-1a version. Why does taking stuff out cause the size to mushroom?


      Second question, if PDF/X1-a flattened the file, why am I getting any change at all when I run the fixup on the PDF I got after I ran that first step?