Rgb workflows – HP DesignJet 500 User Manual
Page 84
Custom emulation
This mode can emulate any CMYK printer. You will
need the ICC profile for the printer for which the CMYK
data is intended. The ICC profile is a standard which
defines which color would come out of that printer. The
HP Designjet uses this information to produce the
same color.
RGB Workflows
RGB is a device-independent definition of color. Being
device-independent implies that RGB has to be
converted to the printer-centric CMYK data which
drives the printer. And this transformation depends on
the target printer.
The transformation from RGB to CMYK requires an
ICC profile for the printer. The profile describes which
CMYK is a good reproduction of a certain RGB.
Because the color which comes out of the printer
depends on the printer setup—such as the type of
paper and the quality level—you must select the ICC
profile for the intended printing conditions.
HP Designjet printers come with ICC profiles
for multiple types of paper.
Even if RGB is printer-centric, RGB data does not
always produce the same color. There are a few
frequently used types of RGB color such as sRGB,
Apple RGB, Adobe RGB, or ColorMatch RGB. An RGB
profile describes what an RGB color looks like.
Your printing application should be set up with the
correct ICC profiles for the RGB and CMYK data.
Newer applications such as PhotoShop 5 and
Illustrator 8 allow you to do this. Your application will
use these ICC profiles to convert RGB to CMYK.
If your design application does not support ICC
profiles, you don't have control over the conversion
from RGB to CMYK. So, always convert data into
CMYK before putting it into the application. Make sure
that the CMYK has been optimized for the printer which
is going to handle the data—see the recommendations
in the previous section.
Some applications send unidentified RGB data instead
of CMYK. In such case, the printer will carry out the
conversion from RGB to CMYK. You must select the
type of RGB data in the PostScript driver, in the “Printer
color management/RGB emulation” option.
For applications such as Adobe PhotoShop
which do identify the RGB they are using,
this setting will have no effect.