Mike Chaney's Tech Corner

Hi,

I've searched the forum but did not find an answer, so here it goes.

On another forum https://www.dpreview.com/forums/post/58860582 (https://www.dpreview.com/forums/post/58860582)) a remark was made that there is not a 100% certainty that all nozzles of a color that are selected get purged. Unfortunately, the poster there did not mention which paper settings were used in the printer driver.

On another forum someone made a remark about the possibility (without further details) of one particular ink being missed, so I'd like to have this cleared up if possible (to prevent the rumor mill from spreading incomplete/wrong information). Maybe there is some more info available that can help in choosing the best media settings in the printer driver, to make sure that the intended colors get proper attention.

For the above mentioned issue of Vivid Magenta not being addressed by choosing Magenta, maybe there is another media choice that would use it?

Also, I've noticed in my media settings for particular media of my Canon printers, only a choice of "Platinum" paper allows me to select the highest printing quality (and thus highest resolution). I'm not sure if that quality setting (2 or 1) makes any difference for the unclogging of all nozzles (by using a different dither pattern), or if that only affects the precision of mechanical positioning.

Sofar I've chosen that Platinum media choice at the highest quality setting of 1, in the assumption that it will exercise all nozzles.

Maybe there are other combinations that will miss some of the nozzles, and should be avoided?

Cheers,
Bart

If you turn color management off in the driver (as you are instructed to when using the unclog pattern), you'll get all the nozzles.  Following on to the post on the other forum, when printing with color management off in the driver, you are basically getting "raw" color.  So when you send 255,0,255 (pure magenta at max saturation) as the unclog pattern does, there's no way the printer won't use vivid magenta: it'll use it because you are asking for maximum "raw" magenta.  It's similar to how color targets are printed when you profile a printer.  The raw values are sent to the printer and very little "mixing" of colors is going on because you want the full color range of the printer and the profile handles the mapping.

Regards,
Mike

Thanks Mike,

That makes a lot of sense. As I said, it was not clear what driver settings were used, so it might have been user error.

Do you think that the high(est) quality setting like 2 or 1 in Canon drivers makes any difference on uniform colors (like in the purge patterns), or is it basically only used for rendering of the finest possible details and color dither mixing?

Cheers,
Bart

Hi Mike

While I'm -almost- certain that the pattern uses all ink's even on plain paper, I'm less certain about all the nozzles.

I've read that the newest Canon heads use 1.28" for the nozzle's.  I would be more comfortable if the vertical patches are about 1.5".  Now I see a repeat of 6 colors horizontal repeated 16 times, I wouldn't mind if those went up to about 20 colors  repeated 5 times on every larger row.

But off course I'm using it as a purge/maintenance print not as an unclog print.  I can image that the current pattern has higher unclog power.

I also would like it to have an aspect ratio that's wider, it's easy to repeat the image several times on one page.  Now I put a A4 plain paper in it, but using a 17" roll paper for it could be handy.

Alain