I have a canon MG5450s multi-function printer that has started to print strange effect on the PGBK ink
Having tried cleaning the head etc., and replacing the ink cartridges, re aligning, has not solved the problem
If it is not a hardware problem, could it be driver / firmware related.
I am using Windows10
I have included an image showing the PGBK part of the nozzle print to explain my problem. Hoping someone can suggest a solution.