Process Color Manual book

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Mon, 24 October 2005 13:07 Go to next message
uw_badgers (Photoshop begginer)
I just bought this book "Process Color Manual - 24,000 CMYK
Combinations", which is a reference book of CMYK swatches. I'm sending
something to a professional printer, and want the colors to be close to
exact.
http://www.amazon.com/gp/product/0811827577/103-9979391-6600 649

Anyways, I checked out a few colors that I know what they're supposed
to look like. I looked up the 2-color combination of 100% cyan, 100%
yellow, and the swatch looked very green. The 100% magenta, 100% yellow
swatch looked very red. But the 100% cyan and 100% magenta swatch did
not look blue, it looked like a darker purple. Why is that? Shouldn't
100% cyan and 100% magenta be a pure blue?
Mon, 24 October 2005 18:09 Go to previous messageGo to next message
Mike Russell (Photoshop expert)
<uw_badgers@email.com> wrote in message >I just bought this book "Process
Color Manual - 24,000 CMYK
> Combinations", which is a reference book of CMYK swatches. I'm sending
> something to a professional printer, and want the colors to be close to
> exact.
> http://www.amazon.com/gp/product/0811827577/103-9979391-6600 649
>
> Anyways, I checked out a few colors that I know what they're supposed
> to look like. I looked up the 2-color combination of 100% cyan, 100%
> yellow, and the swatch looked very green. The 100% magenta, 100% yellow
> swatch looked very red. But the 100% cyan and 100% magenta swatch did
> not look blue, it looked like a darker purple. Why is that? Shouldn't
> 100% cyan and 100% magenta be a pure blue?

Should be, but isn't. Cyan is a weaker ink than magenta. This is why blue
sucks in CMYK, and why you are observing the shift toward purple.

This begs the question of what physical and optical principles are at work
to make this the case. I have no idea. Apparently it is difficult, or
impossible, to make a high quality cyan dye that absorbs only red. If it
were possible, then we would see monographs made with this dye.
--
Mike Russell
www.curvemeister.com
Mon, 24 October 2005 18:47 Go to previous messageGo to next message
iehsmith (Photoshop expert)
On 10/24/05 5:09 PM, Mike Russell uttered:

> <uw_badgers@email.com> wrote in message >I just bought this book "Process
> Color Manual - 24,000 CMYK
>> Combinations", which is a reference book of CMYK swatches. I'm sending
>> something to a professional printer, and want the colors to be close to
>> exact.
>> http://www.amazon.com/gp/product/0811827577/103-9979391-6600 649
>>
>> Anyways, I checked out a few colors that I know what they're supposed
>> to look like. I looked up the 2-color combination of 100% cyan, 100%
>> yellow, and the swatch looked very green. The 100% magenta, 100% yellow
>> swatch looked very red. But the 100% cyan and 100% magenta swatch did
>> not look blue, it looked like a darker purple. Why is that? Shouldn't
>> 100% cyan and 100% magenta be a pure blue?
>
> Should be, but isn't. Cyan is a weaker ink than magenta. This is why blue
> sucks in CMYK, and why you are observing the shift toward purple.
>
> This begs the question of what physical and optical principles are at work
> to make this the case. I have no idea. Apparently it is difficult, or
> impossible, to make a high quality cyan dye that absorbs only red. If it
> were possible, then we would see monographs made with this dye.
> --

I'm curious. I'm not familiar with the book. Reading the description:
"Process Color Manual provides an astounding 24,000 colors that match from
computer display to printed page." I'm dubious. Does the book (circa 2000)
address calibration at all?

inez
Mon, 24 October 2005 20:43 Go to previous message
Tacit[1] (Photoshop expert)
In article <1130173632.138797.55730@o13g2000cwo.googlegroups.com>,
uw_badgers@email.com wrote:

> Anyways, I checked out a few colors that I know what they're supposed
> to look like. I looked up the 2-color combination of 100% cyan, 100%
> yellow, and the swatch looked very green. The 100% magenta, 100% yellow
> swatch looked very red. But the 100% cyan and 100% magenta swatch did
> not look blue, it looked like a darker purple. Why is that? Shouldn't
> 100% cyan and 100% magenta be a pure blue?

No. You can not get pure blue in CMYK; it's not possible.

Bright, saturated blues are outside the CMYK gamut. Nothing you can do
about that; sorry!

--
Art, photography, shareware, polyamory, literature, kink:
all at http://www.xeromag.com/franklin.html
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