According to this manual, the only time iP4200 is printing unidirectionally is when printing grayscale on envelopes.
However, it specifies that there indeed is a matter of the number of passes: 1 pass in normal colour and grayscale printing and 2 passes and more in borderless, photo paper, etc...
Tested that and found out that Duplex Printing is the culprit. Set 'on', and there are coloured striped 'grayscale' prints on both 32-bit WinXP and 64-bit Win7. Set 'off', and there's pure grayscale.
But why on Earth would this electric failure only manifest itself under certain conditions I described?! I mean, one moment it couldn't print a simple check pattern properly, but set to borderless it managed to print 100+ full colour pages, four hours straight, without a hitch. What is so...
I'm rather new to the world of refilling, but here's my story. In short, my printer has colour banding issues with cyan-based colours, but only under certain printing (software?) conditions.
I've a second-hand PIXMA iP4200 with a new print head. Never used it for colour printing, and never...