I have this printer connected to an iMac running El Capitan, but am no longer able to print 2 sided as this option is always greyed out in the printer settings dialog box and there is no way of changing it. This is the case with all software. I have contacted Canon Support but they just referred me to Apple. Apple have investigated very thoroughly and said that there's not an issue with the operating system and that it's the printer driver that's causing the problem. Incidentally, I previously used this printer on a PC under Windows 7 and always had the 2 sided print option. Just wondering if anyone else has encountered a similar problem.
