Canon Today:
Dear Abdo Abdala,
Good afternoon. Thank you for contacting Canon product support. I understand you are looking for the Mac OS X version 10.12 (Sierra) drivers for your imagePROGRAF iPF8400. I realize how important this is, and I can provide you with more information about the drivers.
Even though the pre-released, beta version of the Sierra operating system may have been available for months, we do not update our drivers until the operating system is officially released. Our Engineers are diligently working on drivers for the Sierra operating system. We do not know exactly when the updated drivers will be available. I recommend that you periodically check our web site (click HERE) for the updated drivers for your iPF8400. We apologize for the inconvenience this may cause.
Please let us know if we can be of any further assistance.
Thank you for choosing Canon.
Sincerely,
Sonya
Technical Support Representative