#HP550c GREEN Machine!
7 messages in this thread
Oh no, not again, I wish I never bought this *?!@%&" printer, Can
anyone please tell a weary workbench 3 user why his HP550c prints all
text in black (as it should) but when printing a picture, black
becomes bile green!!!. Its just a little frustrating, I'm using the
standard 550c driver which comes with O.S. 3, and it works fine, all
apart from the slime trick! Thankyou for reading this… HELP!
(please!) *IcE*
As I understand it, HP doesn't recommend using the black ink at the
same time as the colored ink. On a color picture, the printer driver
is forced to 'make' a black using mixtures of YMC. Which is why the
black isn't as black. One of the 3rd party 550C drivers may do a
better job of making blacks than the standard 3.0 driver; it might be
worth your while checking that out.
andy
>As I understand it, HP doesn't recommend using the black ink at the same
>time as the colored ink. …
Andy,
I find that to be pretty interesting that HP would have a recommendation
like that, and yet include a calibration routine on their Macintosh driver
to align the black and color cartridges. (I use one at work.) I'm not
disputing what you're saying, but it seems at odds with what HP has
produced for another platform.
regards,
greg
Interesting. All I can go on is the tech docs produced by HP. Maybe
HP didn't do the Mac driver; maybe it was done by someone who
decided that mixing the inks is OK if you're careful to not let the
colored dots touch the black dots.
The are more reasons for not printing in 4 colors on the DJ 550C. The
bleeding of color inks with the black ink isn't the only problem and can
be nearly cured when using the depletion and shingling function as
recommend in the HP docs.
A more serious problem with low resolution 4 color printers are disturbing
black color dots surrounded by color dots. For instance, the black dots
make a skin surface look rough. Try a picture of a face. Printing with 4
colors result in very visible black dots in the skin area. The problem
becomes even more visible when using error diffusion dithers like Floyd
Steinberg in areas with a saturation >50%.
Another thing most people don't think about: speed. Depending on the
graphic/dither you are printing, 3 or 4 color printing method can differ a
lot when it comes to printing speed. Often 3 colors are much faster.
— Wolf Faust, Am Dorfgarten 10, 60435 Frankfurt, Germany —
But the problem that stays is that you can create much more shades of
color using 4 colors (that's why people have invented the CMYK separation
instead of CMY). The Colors Cyan Magenta and Yellow can not be produced as
clean as neccesarry. So you use the fourth color to recompensate for
that.
There are very intelligent color removal algorithms for the problems you
mentioned. The problems of roughening and so on is not really one of the
low resolution printers, but it is merely more visible.
… over the ocean
Jochen, Stuttgart, Germany with AutoPilot
the problem can't be solved by color removel. Sure, you can print
more colors with 4 colors (not much more… but there are other
aspects that require 4 colors). But this doesn't mean it's better.
Please read my message again and please… we're talking about ink
jets in practice… not a 2560dpi printer (we can start a new
subject on this if you wish).