Reply To: Creating an Interactive PDF with a small file size?

Probably not.

“Only text and vector graphics” doesn't necessarily imply the file ought to be small. What if you have a lot of text? (And 400 pages certainly sounds like a lot.) Vector images cannot be downsampled, so you're stuck with those as well.

Best is to check with Acrobat Pro's “Optimized PDF” where all the bytes go — sometimes, you can simply discard large chunks of data, such as color profiles per image, or fonts embedded in their entirety.

If that doesn't work, you can always tell your clients the truth: the file is large because there is a lot of stuff in it.