# Does it make any difference compressing a file during exporting or after?

I have an InDesign file with a number of vector images in it. I was wondering whether it made any difference whether I exported a full quality version and compressed the resulting pdf or exported a lower quality version with no subsequent compression. Is there any reason to choose one over the other?

• What sort of compression are you considering? InDesign can compress (and downsample) only bitmap images. That is not a useful operation on vector illustrations. – usr2564301 Aug 13 '15 at 17:46
• I do it after, for reasons mentioned here (see answer + comments): graphicdesign.stackexchange.com/questions/45148/… – go-junta Aug 13 '15 at 19:31
• Vector images have no "full quality" or "lower quality"; they are rendered according to the output device in the graphic subsystem or in the RIP. – Max Wyss Aug 13 '15 at 21:19

In general, I've found that opening the exported InDesign PDF with Acrobat and then resaving using Reduce File size . . . in Acrobat results in smaller files without any significant loss of quality (for proofing). I use a custom Job Option when exporting from InDesign for proofs. The custom Job Option is slightly better than the "Smallest file" option -- images down sampled to 125ppi, no bookmarks, hyperlinks, etc.