Color is a sensation caused by the interaction of a light source, an object (ink on paper) and an observer (you). If any of these variables change, so does the color. If a goal is consistent color, then these variables or factors need to be controlled and standardized. For now, let’s just discuss the light source.
The international standard for viewing condition in the printing industry is called ISO 3664. The current version is from 2009. It specifies many technical parameters concerning lighting, such as chromaticity or color temperature, intensity or brightness, evenness, surround, and others.
At TBN Direct, our printing press consoles are equipped with the proper lighting according to this ISO standard. However, if our customers do not have this same lighting condition, then when you view the proof or press sheet, the color may look different than when we view the proof or press sheet. The technical term for this is called metameric or metamerism. It means two things that look the same under one light look completely different under another light. For example, when purchasing clothing inside a store under fluorescent lighting, the color may not appear the same when viewed at home under incandescent lighting or outdoors under daylight.
Pantone realizes the importance of proper lighting conditions and the effect it has on viewing colors. They now include in their formula guide books, a light indicator at the very back. When the two metameric stripes match the lighting color is correct for daylight or D50 (meaning daylight at 5,000 Kelvin). If they don’t match, we shouldn’t be using this light for critical color evaluation and judgment.
If you have any questions about this Tech Talk article, please contact Steve Suffoletto at firstname.lastname@example.org