Color, Light, and Metamerism in Print
Have you ever carefully coordinated your outfit before leaving the house, only to find your clothes don’t quite match once you are outside or under the fluorescent lights at work? If so, you have experienced a form of metamerism–a phenomenon that occurs when two colors appear the same under one set of lighting conditions, but appear visually different under different lighting conditions. Metamerism can have a significant impact on print production, creating issues with color accuracy and consistency between printed pieces.
What causes metamerism?
The human eye sees color differently depending on a number of conditions. Brightness, temperature (warm vs. cool tone), and specific wavelength can vary widely between different light sources, influencing the way objects and colors are perceived.
When matching two printed color samples–such as a press sheet to the proof–samples are typically viewed under industry standard lighting conditions (5000K/ D50) in a light booth. But this lighting may be very different from the end conditions where the printed pieces will be used (i.e. a POP display in a store, outdoor signage, or product packaging viewed in a consumer home). If printed pieces fail to retain their color accuracy across these different light sources, they will appear visually different from the original match. Additionally, campaigns that utilize multiple different materials and technologies (such offset printing and silkscreen printing) to produce matching pieces can run the risk of metamerism when compared under different lighting conditions.
Tips for identifying and preventing metameric failure:
- If your campaign requires printing on different substrates and/or utilizing several different print processes, keep in mind that slight visual differences in color may occur. Your print partner will work to minimize these differences and ensure color consistency and quality across all project components.
- Make sure your print partner knows how the final products will be viewed–especially if color is critical and needs to align across different lighting conditions. This will help them to create the best color match.
- During press checks, use a light booth to view printed samples under a variety of lighting conditions and ensure they match under each condition.
- Verify your viewing light source meets standard conditions. On the back of every Pantone PMS book, there is a useful indicator tool to help determine whether your lighting meets 5000K/ D50 industry lighting standards for proper color evaluation. The two indicator patches appear to be different colors under various lighting temperatures, but under standard lighting the two patches will match.
Imagine! Print Solutions is committed to helping you execute compelling campaigns that meet your brand standards and project vision. Partner with us to ensure color accuracy and consistency in your print campaigns.