Signage Education | Color Management Part 3, What factors affect the representation and perception of color?

Effective color management requires a well defined process that accounts for the many factors that can affect color. In this, the third part of a series of articles on Color Management, we’ll explore the various factors that affect the representation and perception of color.

A proper color management process involves many disciplines, all aimed at ensuring predictable color output.

Lighting

If you’ve ever taken a photograph in fluorescent lighting, you likely have seen an unnatural hue in the photograph that wasn’t evident in the room photographed. Oversimplified, each light source has its own color characteristics. Ideally, a color production environment should have lighting that closely resembles natural outdoor lighting. Sadly, most sign shops use whatever lighting was in place when they signed their lease. Most often, that’s fluorescent lights with Cool White bulbs. Though inexpensive, Cool White bulbs produce light with very poor quality of color. The measure of color quality, or CRI (color rendering index) for these bulbs is 62. Oversimplified, this means their color output is only 62% of natural daylight. As such, our perception of displayed or printed images can be significantly skewed. A print that looks good under Cool White fluorescent lighting will not look good when taken outside to be viewed in natural daylight. Though more expensive, there are fluorescent bulbs available that yield a significant improvement in color quality. For example, Daylight bulbs have a CRI of 79 at a moderate increase in price compared to Cool White. For best results, full spectrum fluorescent bulbs have a CRI of 98, but are typically 10 times the cost of the least expensive bulbs.

Environment

In digital printing, temperature and humidity can affect color output. Your printer, its ink and the media you use are all affected by changes in temperature and humidity. If you think of printing as a chemical reaction, it’s easy to see how even minor changes can affect the reaction, and noticeably affect the appearance of printed output. For example, ink will dry faster when printing in a warm environment compared to a cooler environment.

Media

In digital printing, “media” refers to the material bring printed. This may be PVC film, paper, banner material, as well as others. Even within the same manufacturer, each of their media types are engineered for a specific purpose. The material used, composition and manufacturing process varies between media types. As such, the manner in which media accepts ink varies. The interaction of ink on media and the amount of ink needed to saturate media will similarly vary. Even the same product line from the same manufacturer with different surfaces (matte vs glossy) will affect printed output.

Ink

Ink is a liquid that contains dyes or pigments to color a surface. Ink can be a complex medium comprised of many materials, colorants, binders, additives, carriers, etc. Every manufacturer’s “recipe” for ink varies, so a change in ink manufacturers will affect the reaction between ink and media, which affects color output.

With so many factors that impact color output, an understanding of these factors is important in developing a color management process. In upcoming articles, we’ll identify various methods of eliminating or significantly reducing the variables that can adversely affect color output.

For more information, contact:

Spectrum Signs
23382 Madero Suite L
Mission Viejo, CA 92691
(949) 297-3800

Spectrum Signs