CMYK is BAD
CMYK is BAD
- Subject: CMYK is BAD
- From: "DuWayne" <email@hidden>
- Date: Tue, 29 Oct 2002 01:09:25 -0500
From: Marc Levine
>
DO handle these "multichannel" devices as CMYK. Best, Colorburst,
Colorbus,
>
Harlequin, Onyx, Wasatch, and many more work in this way. The reason this
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method is so popular is because this is the correct way to handle these
>
types of printers!
4 color CMYK a bad way to handle multichannel devices becuase you think your
getting controlling.
Putting Roland Ornage/Green aside. It assumes that Light Cyan & Light
Magenta are the same ink.
When you dilute the ink by 50plus % do you really think that they will have
the same soectral response, big maybe.
Who says that the manufacture are just diluting, I believe some are using a
different dye or pigment.
This causes big problem when trying to do CMYK UCR/GCR calculations.
>
keep in mind that light ink has a single purpose - to
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create a smooth blend (especially in midtone and highlight regions).
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Therefore, the RIP should handle the relationship of light and dark inks
so
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that it can properly mesh the two together in the "screening" process.
This is why rips print bad, the driver had a fixed blending point. The
blending point is media depended usually becuase of density issues. Where
is the rip going to data for each media? -- the media profile - that's why
treating multi channel devices as 4 color problems. Ever see a nice line or
bloom in the middle of a skin tones - here is one of the reasons
>
Of course, additional primaries can
>
be added (other colored inks such as orange, green, blue, red, you get the
>
picture). In such a case, a multi-channel profile would be necessary.
I believe its easier to profile with 4 channel CMYK when there are extra
primarys such as OG than light cyan light magenta.
The reason is that you don't have to fight density spikes and the profile
software has a lot of setting to deal with off-color primaries. If you
mixed the Orange with Magenta & the Green into the Cyan it would be no
different than profining inks for silk screen, flexo etc.. which tend to be
off-color. A lot of the profile software is designed to deal with these
off-color inks in the formulas.
>
As a side note, I like to be clear that light inks do not increase a
>
printer's gamut. Any color you can make with light-cyan, you can make with
cyan.
I haven't tried it but 1) It assumes that the light inks are justed diluted
versions and thats questionable 2) There is a lot of spectral/colormetric
room between 1% patches of each CMYK Channels. As for more gamut its
splitting hairs becuase I can probably print a color with the light versions
that I can't print with regular cyan becuase their would be more like
reflection from a light solid than a halftone. So if I can print color with
the light inks that I can't print with the "normal CMYK" is that more gamut?
I can proably cuase a spike out side of CMYK with light inks especailly if
the are different pigments/dyes in the lights.
>
This is why you DON't see Epson using a light yellow ink - you
>
can't see the edge of the droplets anyway, so why add a light color?
This you would has to ask Epson becuase I believe that there are few desktop
models sold in Japan market that do uses light yellow.
>
Anyhoo, it is true that not everybody uses this method for working with
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these types of printers. From some responses, I understand that Photoprint
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handles these devices as RGB.
Its pure CMYK rigged to try to handle 8 Channels.
>
In fact, you CAN'T do any of that control stuff!
This is why the most rips/printer drivers don't print correctly --- they
lack controls on something that needs to be controlled or the controlls are
so comples that the average user has no chance.
DuWayne Rocus
Omniscience, Inc
South Florida Roland Dealer
(954) 584-2949 (954) 316-4841 Fax
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