Getting quality screen shots for documentation

I'm having trouble with low-quality screen shots in my printed (PDF)
documentation.

I have a big, high-resolution monitor for 132-column screen formats with
the Andale Mono font and use SnagIt to get full-screen images as .jpg's. I
don't do any post-processing (like stripping out colors). I drop the plain
jpg's into Madcap Software's "Flare" single-source authoring tool and get
HTML, PDF, and Word (to name a few). In HTML format, the images (1536 x
840 pixels) are good. In Word and PDF format, they're not good at 660 x
355 pixels.

The Word and PDF quality was fine when I used Client Access. The
degradation in image quality was immediately obvious when the Java-based
emulators took over--it was a gut punch and the only time I remember the
replacement product being worse than the original (and I used WDSC). I had
a flashback to the days I was forced to use a Decision Data 5250 knockoff.

I'd be grateful to hear how others deal with image quality issues (short of
installing Client Access on a Windows 10 box, or maybe with a Win 7 VM).
I'm considering 3rd party emulation and Photoshop-type applications.

Thanks!

-rf