We have an in-game journal in the game, some sample pages are attached. The journal is made in psd and The settings I used when saving the PSDs as PDFs in photoshop:
-Under Format menu, select Photoshop PDF
-Under General tab, the Adobe PDF Preset is [High Quality Print]
-Under General tab, uncheck Preserve Photoshop Editing Capabilities
-Under Compression tab, Image Quality should be High (not Maximum)
We render the pages to 1024x1024 pixels... So its roughly like viewing it on a 1080p screen.
I looked up some questions pertaining to this http://graphicdesign.stackexchange.com/questions/10692/why-is-my-pdf-so-huge and tried a few options (not all as I am not a photoshop expert and don't have illustrator either).
Unfortunately it looks like the background is repeated on every page... Now again because I don't know PDFs I have no idea if its possible but ideally the background image would only repeat once, and the little images would be super-imposed on top of them. This would cut the size by like 75% I'm guessing. But I have no idea how you set up a PDF to export that way...
Also if the background image was separated it could be lower resolution and get away with it (since its blurry/softer) and the line art could still be higher resolution.
We would welcome applications from people who know Photoshop/Illustrator and File Compression to PDF well and can work on this problem