Currently when you want to export a projet timeline you got only two options : PNG - a blurry low resolution image, or Excel - without the GANTT planning view.
During meetings with customers or partners, we are currently using an other planning tool that give us the ability to export event big planning timelines (3-4-5 months) as a PDF file with perfect quality for the screen and for printing.
Usually for theses meetings we sent the planning by email before and then print it on A3 size paper several copies, everybody participants have one and can take notes on it.
As open source PDF export framework are existing, too bad that Wrike doesn't provide this feature yet.
Regards
Julien