Whether you are displaying soft proofs or producing hard-copy proofs, predicting press behavior requires a color management system. The CMS lets you create color profiles that characterize specific devices so that one can mimic the other. However, unless you maintain a stable environment, i.e. institute quality control standards, those profiles are virtually useless.

The reason is simple. The color profile was created under certain conditions. Changing just one of those conditions can affect color behavior. The profile, therefore, is working with a different set of specs than you are.

Removing the butterflies

Chaos theory states that complex or chaotic environments are sensitive to their starting conditions. The “butterfly effect” states that the tiniest change in conditions, like the flapping of a butterfly’s wings, can make predicting the behavior of a complex environment impossible. While this discovery was based on the study of meteorology, I cannot help but see a parallel in prepress. If we make sure the starting conditions are always the same, we can then predict press behavior with a high degree of accuracy.

The tonal values of a proofer, for instance, can vary over the course of a day. So even when using the same color profile on the same proofer, the color may shift in a proof printed in the evening from one that was printed early in the morning. A quality control regimen means you verify that the proofer is printing with the same tonal values in the evening as it did in the morning, and if it is not, you recalibrate using the same target that was used in the morning.

Using the same target or standard is key to maintaining a stable environment. In other words, you need to ask the same question and get the same answer.

Quality control needs to encompass all the variables that can affect color. Application software also influences color perception. Image-manipulation software, such as Adobe Photoshop, comes with its own color settings. Once again, the key to avoiding problems is consistency. Always use the same application settings to maintain a stable environment.

Knowing the many variables that can influence color will help you to develop a checklist for maintaining stability and implementing quality control.

Monitors

• Aging affects consistency of color displays as the phosphors tend to degrade with time.

• Temperature affects monitor brightness, so color can vary from morning to night depending on the length of time the monitor was in use.

• Different makes and models have different characteristics regardless of the operating system and software.

• Graphics cards use their own look-up tables for color characteristics.

• Desktop wallpaper can alter the way colors appear. Black provides the best backdrop for true color.

Proofers

• Every proofer, regardless of make and model, has its own tonal characteristics.

• Piezo proofers have a wider color gamut than thermal proofers.

• Six-color proofers have a wider gamut and smoother tonal rendering than four-color models.

• Dye inks have a much wider color spectrum than pigment inks.

• Age and length of time the system has been running affect color.

• Paper cast, opacity and texture affect color reproduction.

Software

• Different programs use different algorithms to interpret color.

Ambient condition

• Fluorescent (blue) lights are harsh and tend to whiten colors.

• Incandescent (yellow) lights are soft and tend to make colors look warmer.

Rosemarie Monaco is the chief executive officer of Group M Inc., a marketing communications and consulting firm specializing in the graphic arts. Send comments and questions to rmonaco@groupm.org.