CMYK gamut question (?)

[SonicBooom]

Anyone know the answer to the question below... ?

In Freehand, I created an RGB colour, and the CMYK equivalent from the colour
mixer. The two colours appear different, as would be expected. I'd also presume
that the CMYK equivalent colour is the closest match to my RGB colour as far
as Freehand is concerned.

Example... R128 G128 B255 / C38 M29 Y0 K0 - The RGB is quite bright, and the
CMYK is dark and a bit grey.

I applied those colours to different objects in Freehand and printed the
document. The CMYK coloured object prints as would be expected, but the RGB
object prints a colour closer to the RGB on the screen.

This makes me wonder if some printers can print colours that Freehand would
consider out of the CMYK gamut?

I came across this while printing on my deskjet printer. I presume that
similar things would happen on professional printers?

I thought I came across a similar thing before when I printed Pantone colours
using a CMYK printer while I was studying at college a few years ago. The
Pantone colours seemed closer to the original colours. Even if the CMYK
equivalent colour seemed not to exist.

Alastair

[Rich Hudgins]

Simple answer:

CMYK Ink Jet inks do not equal CMYK printing press inks
cannot compare

Rich

SonicBooom wrote:

> Anyone know the answer to the question below... ?
>
> In Freehand, I created an RGB colour, and the CMYK equivalent from the colour
> mixer. The two colours appear different, as would be expected. I'd also presume
> that the CMYK equivalent colour is the closest match to my RGB colour as far
> as Freehand is concerned.
>
> Example... R128 G128 B255 / C38 M29 Y0 K0 - The RGB is quite bright, and the
> CMYK is dark and a bit grey.
>
> I applied those colours to different objects in Freehand and printed the
> document. The CMYK coloured object prints as would be expected, but the RGB
> object prints a colour closer to the RGB on the screen.
>
> This makes me wonder if some printers can print colours that Freehand would
> consider out of the CMYK gamut?
>
> I came across this while printing on my deskjet printer. I presume that
> similar things would happen on professional printers?
>
> I thought I came across a similar thing before when I printed Pantone colours
> using a CMYK printer while I was studying at college a few years ago. The
> Pantone colours seemed closer to the original colours. Even if the CMYK
> equivalent colour seemed not to exist.
>
> Alastair
>

[Judy Arndt]

What desktop printer are you using? Many inkjet printers such as the Epson
Stylus Photo printers are optimized for RGB digital photo output. Such
printers work best with RGB input. Their color gamut is much wider than CMYK
offset press.

What is your color management setup in FH? The conversion of RGB to CMYK
colors in the Mixer uses color management settings active at the time of
conversion. If you have color management set to 'None', then your light blue
R128 G128 B255 will become 50c 50m 0y 0k.

If you're designing for print on a CMYK offset press, I suggest you get
yourself some Pantone Process Guides. If you need to work with both spot and
process colors, get the Pantone Solid to Process Guides.

Judy Arndt


SonicBooom wrote:

> Anyone know the answer to the question below... ?
>
> In Freehand, I created an RGB colour, and the CMYK equivalent from the colour
> mixer. The two colours appear different, as would be expected. I'd also
> presume
> that the CMYK equivalent colour is the closest match to my RGB colour as far
> as Freehand is concerned.
>
> Example... / C38 M29 Y0 K0 - The RGB is quite bright, and the
> CMYK is dark and a bit grey.
>
> I applied those colours to different objects in Freehand and printed the
> document. The CMYK coloured object prints as would be expected, but the RGB
> object prints a colour closer to the RGB on the screen.
>
> This makes me wonder if some printers can print colours that Freehand would
> consider out of the CMYK gamut?
>
> I came across this while printing on my deskjet printer. I presume that
> similar things would happen on professional printers?
>
> I thought I came across a similar thing before when I printed Pantone colours
> using a CMYK printer while I was studying at college a few years ago. The
> Pantone colours seemed closer to the original colours. Even if the CMYK
> equivalent colour seemed not to exist.

[SonicBooom]

I'm using an Epson Stylus C60 for test prints before I send the files off to
the printers.

My colour management is normally set up to Kodak Digital Science, but to be
honest, I have no idea which one I should be using, or, which one if any, is
used as the main one universally.

I do graphic design and web design, but have been doing much more web design
recently. I find it so annoying that I can get great vibrant colours on the web
pages, but can't print the colours on CMYK printers... :(

[Ken Kehl]

Here's something else to take into account.

As Judy pointed out, Epson inkjet printers have been optimized for RGB
content. Historically, part of that optimization is a built-in color
space conversion that 'pre-converts' all input to RGB, even though the
printer has the CMYK inks to print them as-is. So, if you feed a CMYK
color to an Epson, it converts it to RGB, then converts that result to
the nearest equivalent in the color gamut available in the inks of the
printer, be they 4, 6 or more.

In other words, CMYK color data gets converted twice, RGB colors only
once.
______
Ken
ellipsis design
(remove the _xx_'s)

[SonicBooom]

Therefore, deskjet printers, at least, EPSON ones, are not suitable for test
printing colours.

Another question :)
I've got my colour management in Freehand set up to Kodak Digital Science,
which seems to be fine for everything I do in Freehand. However, I input the
same CMYK values when typing text in Word and it seems to only use the RGB
equivelent instead... I guess this is because the colour managment is set up
differently. So when I print to my EPSON printer I get a colour closer to the
RGB values.

Is there a simple way to see what CMYK value is required when the colour
managment is set to NONE?. I'm soooo confused! Basically I want to send off my
letterhead to print at professional printers, and then type up letters in word
and print using the same CMYK value, which is c50 m100 y0 k0

[Judy Arndt]

Word speaks RGB. Your printer speaks RGB and translates is internally to
proprietary inks. When you talk to both in a foreign language -- CMYK,
don't be surprised if they don't comprehend you!

In Word, set up a swatch page 'pictures' or large bold text of varying RGB
mixes. Label each with the RGB mix used. Print it to your inkjet printer.
Choose the RGB mix that is the closest visual match to your CMYK printed
letterhead and use that in Word.

BTW, did you buy those Pantone swatch books that I advised you to? A graphic
designer without Pantone swatch books is like a carpenter without a
measuring tape. :-)

Judy Arndt

SonicBooom wrote:

> Is there a simple way to see what CMYK value is required when the colour
> managment is set to NONE?. I'm soooo confused! Basically I want to send off my
> letterhead to print at professional printers, and then type up letters in word
> and print using the same CMYK value, which is c50 m100 y0 k0

[SonicBooom]

Thanks Judy Arndt,

I've not yet got myself a book of Pantone colours. I'm not sure which ones I
should be getting though... The vast majority of work produced by myself will
be printed on printers that wont be using Pantones. My main use of a swatch
book would be to show what different CMYK colours can be used.

Pantone Solid to Process colours swatch book? And from where?

Alastair :)

[Odysseus]

In article <c6lvml$iur$1@forums.macromedia.com>,
"SonicBooom" <webforumsuser@macromedia.com> wrote:

> I've not yet got myself a book of Pantone colours. I'm not sure which ones I
> should be getting though... The vast majority of work produced by myself will
> be printed on printers that wont be using Pantones. My main use of a swatch
> book would be to show what different CMYK colours can be used.
>
> Pantone Solid to Process colours swatch book? And from where?
>

If you're working mainly in process and 'from scratch' (i.e. not needing
to convert existing documents with Pantone spot colours), I'd recommend
that you get the Pantone Process System swatchbook instead of the Solid
to Process one. It gives a much better representation of the CMYK gamut,
having been designed for the purpose rather than to simulate spot inks.
There are other such systems, like TruMatch, but I've never had one of
their swatchbooks so I don't know how they compare to Pantone's.

--
Odysseus

[Ken Kehl]

On Fri, 23 Apr 2004 13:17:25 +0000 (UTC), "SonicBooom"
<webforumsuser@macromedia.com> wrote:

> Therefore, deskjet printers, at least, EPSON ones, are not suitable for test
> printing colours.

That's an erroneous conclusion. Like most other proofing methods short
of an actual press run, it depends on your definition of "suitable".
Inkjets don't use the same inks that offset printers use, so an exact
match is probably out of the question. Can they get close? Probably
close enough. A 4-ink 'desktop' inkjet being driven by a PostScript
RIP will run CMYK throughout the process, so if you want to avoid the
color conversions, it can be done.
______
Ken
ellipsis design
(remove the _xx_'s)