10-07-2019 08:56 PM
I too have had the same problem (described by many) of printing double characters. I have three MX922 printers and love them, except for this problem. Two of them print double characters and one prints perfectly.
The problem has been very well described by Echobot on another thread. Here's a link to the thread:
Like others have suggested, I can change the black font to a colored font, and the problem goes away. I can also tell the printer that I am using matte paper then print with black and the problem goes away.
I called Canon tech support this afternoon and spent about an hour on the phone (most of it on hold). "Quinton," told me that my print head was warped. I asked him why I could print in color or with "matte paper" and the problem went away. He put me on hold for another 15 minutes doing some research. When he came back he told me that when you use colors, the print head uses different nozzles and when you use "matte paper", the print head uses the small black tank nozzles vs. the large black tank nozzles.
So I swapped the print head from my good printer to one that is printing double characters. Sure enough, the problem followed the print head. My good printer started printing double, and one of my bad printers started printing perfectly. Then I swapped the print head back, and the problem again followed the print head. I guess Canon tech support is correct. The double characters are caused by the nozzles used by the large black tank being warped (bad print head).
The posts I have read seem to indicate this problem starts after a year or two -- so I guess that is the life of Canon print heads. The solution appears to be to buy a new print head. Print heads cost more than a new printer (which is REALLY sad). So it all depends on how much you like your existing printer vs. the printers Canon (and others) are now offering.