Page 150 - Graphic Design and Print Production Fundamentals

138 Chapter 5. Pre-press
done with the same library. The problem becomes worse when we combine files from different software
vendors, as designers often have to do when building a document. It is common these days to bring
together graphics created in Microsoft Office and Apple software and generate a final document with
Adobe InDesign. The best way to create consistent documents for reproduction is to specify a common
CMYK colour value that will print reliably on the output device.

Pantone also publishes a swatch book that shows the difference between the swatches run as spot
colour ink mixes, and the same swatch printed as halftone screen builds of process inks. This is a
designer’s most valuable tool for specifying process ink recipes. It also illustrates that many Pantone
colours cannot be simulated very well using halftone screen values of the four process inks. It is very
apparent that very vibrant orange, purple, and green Pantone spot colours are not achievable with process
inks. There are systems like Hexachrome for colour separations that use more than just CMYK inks
to extend the gamut of the Pantone colours that can be reproduced. There are also more and more
inkjet and electrophotographic engines that will use extra spot colours to extend the colour range of the
device beyond CMYK. The businesses that employ those devices usually know they are unique in the
marketplace and have developed marketing tools to help designers use those capabilities successfully.

Accuracy in Design

If we reflect back to the concept of WYSIWYG for a moment, we can use the Pantone selection process
to illustrate the challenge very well. If we ask a designer to choose colours for a document based on
computer screen displays, we know that the RGB or HSL values they can select will be far too vibrant for
reproduction with any imaging engine. To set proper expectations for WYSIWYG, we ask the designer
to calibrate a monitor and select the proper output profiles to tone down the screen view and set more
realistic expectations. We also ask that a print designer use printed swatch books to select from a library
of specified colours and assign realistic CMYK process colour values to her or his colour palette. If
those steps are followed, there is a very reasonable chance that the process will achieve WYSIWYG.
However, it can break down in a few places. The spot colour swatch books set expectations about colours
that cannot be achieved with process inks. When a mixture of spot colours and process inks are used, it
is difficult to display both on the same computer screen with reliable colour. Graphics files can originate
in different software with different libraries using different process colour recipes for the same Pantone
colours.
There are also many spot colour libraries to choose from, and designers don’t know when to use each
library. We have described why the Pantone library is a North American standard, and some of its
limitations. There are other design communities in the world that use spot colour libraries that are
included as choices in graphic creation software tools. There are almost as many spot colours to choose
from as there are free fonts files to download from the Internet. Spot colour classification has led to
thousands of discrete colours being given unique names or numbers. There are several industry standards
in the classification of spot colour systems. These include:

• Pantone, the dominant spot colour printing system used in North America and Europe.
• Toyo, a spot colour system common in Japan.

• DIC colour system guide, another spot colour system common in Japan.
• ANPA, a palette of 300 colours specified by the American Newspaper Publishers Association
for spot colour usage in newspapers.