Page 133 - Graphic Design and Print Production Fundamentals

Graphic Design 121
association persist, you must save the file and check the option to embed the current colour profile.
Assigning a profile will change the onscreen appearance of the file but not alter any of the file’s tint
values (colour data). We are simply instructing the computer on how the original CMYK or RGB values
would look if they are coming from our new source (described in the look up table of the new colour
profile).

Convert to Profile is an immediate and irreversible (once the file is saved) transformation of the
document’s tint values. The assigned profile is used as a source and the user selects a destination profile
and rendering intent. The conversion takes place and the file now has new RGB or CMYK numbers as a
result. If you use the advanced dialog to specify a device link profile, then the currently assigned source
profile is ignored for the calculations since the device link contains information for both the source and
destination conditions.

Both the Assign and Convert dialog windows come with a Preview check box that will allow you to
toggle between the before and after state to visually validate your choices and experiment with the
effects of choosing different rendering intents.

Assessing the Effect of a Colour Profile

Once the profile is applied, what should we be looking for? Both on screen and when comparing hard-
copy (printed) samples, there are specific areas of the image that should be checked. There is also
industry-specific language used in describing colour appearance that it is helpful to be familiar with.
The areas of the image to pay special attention to are saturated colours, flesh tones, neutrals, and the
highlights. Proof and print sample sheets will have four or five images that emphasize these areas along
with tone ramps in the process and overprint colours. Focusing on these areas of interest will make it
easiest to identify variation when checking for colour matching.

The terminology that is often employed is colour cast, to indicate a shift toward a particular colour;
heaviness, to suggest excessive tone (particularly in the highlights); dirty, to specify too much
complementary colour resulting in greying; and flat, to describe a lack of contrast and/or saturation.
Knowing the terminology will help you understand the comments your co-workers may make and will
help remind you of the types of analysis you should be doing.

Additional Colour Tools in Adobe Acrobat

In addition to the fundamental profile handling procedures described above, there are several powerful
and useful colour tools in Adobe Acrobat that can be used once you have exported your desktop file
to a PDF. These are found among the Print Production Tools in the Acrobat Tools menu. Two are of
particular note: Convert Colors and Output Preview.

Convert Colors allows you to convert colour spaces, such as changing RGB content to CMYK. It
also enables transforming spot colours (such as Pantone) to CMYK. In addition, if the file incorrectly
contains multiple instances of a spot colour that should all appear together on the same printing plate
(i.e., Pantone 283 and special blue), they can be linked to behave as a single entry on the colour palette.

Output Preview does not apply any changes to the file, but is an extraordinarily powerful review