This article examines the benefits of color management and uses an actual job to demonstrate how color can be controlled.
Compensation curves Compensation curves are used to correct dot percentages for both screen and digital printing. This is the most common method for correcting color. Here, the builds in the file are changed according to a table of compensation values in the imagesetter or digital press. Compensation curves work well, but few companies actually apply a compensation curve for each color. And among those that do, many cannot apply UCR or GCR. Although color is being managed, this scenario isn't really a true example of color management.
The infrastructure of any sort of color-management system must be maintained to ensure that a set of builds produces the same colors the next time it's used. Digital devices need to be monitored and re-linearized or re-profiled when they drift out of specification. Screen printing relies upon consistency in file-prep, films, and screens. When the same builds no longer produce the same colors, one must carefully consider the situation and either eliminate the source of the variation or adapt.
Once you have a color-managed workflow in place, you'll find that color-managed files are far easier to print than curved files, whether digitally printed, fixed in film, or imaged onto a screen. Color-managed files are also easier to create. Prepress can create files that are proofed and approved, eliminating the need to create builds for each device.
The color of the substrate must be taken into account. Any white elements in the graphics will be the color of the stock. There is no getting around that unless you flood each sheet with white ink. Color management allows you to choose whether or not to simulate the color of the stock. However, stock simulations in the proof or print are so light and so near to neutral that they are best left alone. Pratt uses relative colorimetric rendering, which does not simulate the stock color but does include the stock's color in every build. The only practical way to accurately proof the effects of stock color is to proof and print on the same substrate.
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