Archived from groups: comp.periphs.printers (
More info?)
Bill wrote:
>zakezuke wrote:
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>>>So how do you know this to be true? Have you tried looking at the
>>>printhead laying down the ink on plain paper. You can easily see the
>>>pigment black AND the CMY both being used.
>>>
>>>
>>I noticed this once when on my ip3000 I was running out of a color,
>>probally magenta. I was printing some lyrics and wanted some cyan and
>>others black. All the colors were skewed due to the lack of the
>>magenta including the black text, which I found very odd as it was text
>>and assumed that was covered by the bci-3e black.
>>
>>I don't understand the rhyme or reason of the driver choosing go to
>>color or dedicated black.
>>
>>
>
>The Canon print engine in these models is document oriented, so they do
>not discern the difference between black and colour within a single
>document. It converts the entire document and then uses either black or
>colour inks for the document based on its minimum requirements.
>
>HP print engines are object oriented and can print black text with black
>ink, and colour graphs with the colour inks, all within the same
>document.
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>> I'm told 80% is the usual threthhold, but
>>when I observe things like this happening I simply have no idea.
>>
>>
>
>The 80% threshold relates to photos and how the Canon iP3000 will lay
>down the pigment-based black ink for very dark areas since the CMY black
>is not as dark.
>
>The iP4000 improves photos very slightly by using a dye-based black for
>photos. But after viewing photos from both printers, it makes little
>difference with glossy paper since Canon papers are nanoporous and
>adsorb the ink below the surface. The final print is very glossy and the
>pigment ink is barely noticed.
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Wrong. If you set your paper for plain it uses the glossy black. If
you set it for photo paper then it uses the dye black. It does not
consider the subject. In the case of the IP4/3000, the IP4000 uses dye
black when printing photos when photo paper is selected while the IP3000
mixes the black from the 3 colors. The difference is striking on
certain photos. Both printers use the pigmented black when plain paper
is selected.
>HP photo paper is of the swellable type, and the ink tends to sit near
>the surface. The final print is very glossy, but at first appears etched
>because the heavy layer of CMY to make black is thick and takes a while
>to be adsorbed by the photo paper.
>
>This is why Canon prints are so much more water resistant to HP prints.
>You can actually run a Canon print under water, and gently wipe it dry.
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>
This is bullshit. I had a drop of water land on a photo and it made a
round discoloration that could not be removed.
>But HP prints must be allowed to dry without wiping it or the ink will
>be smudged. Once allowed to fully dry for 24 hours, HP prints are
>generally smudge resistant. But fresh out of the printer they may smudge
>with moist fingers.
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