Have you tried the print driver's bottom plate cleaning and roller cleaning functions? Are the papers flat or slightly curled as it appears the black is close to the trailing end of the paper. Have you tried the custom settings paper abrasion (I believe this opens the platen gap a bit)?
Check your Canon website to see what drivers are available. You will notice the 9500 is not supported by Win10 while the 9500 MK2 is supported. If you are considering updating your OS at some future date, then you may want to take this into account in your purchase decision.
http://shop.usa.canon.com/shop/en/catalog/bci-3ebk-black-ink-tank This is a link to Canon for the BCI-3e black cartridge compatibility. The compatibility button at the bottom of the page will take you to the printer listings. This should provide you with a starting point for your search.