Obj flate_hint = objset.CreateArray();
flate_hint.PushBackName("Flate");
flate_hint.PushBackName("Level");
flate_hint.PushBackNumber(9); // Set max compression vs speed.
For more info, please see:
https://groups.google.com/d/topic/pdfnet-sdk/wCK-rAmEPr0/discussion