The most widely used tool to evaluate color is the human eye. According to experts at Teknor Color, Pawtucket, R.I., a person with average color vision can see about 10 million colors. But there are limitations: People tend to overestimate their abilities and color perceptions can vary widely. Also, the human eye cannot make precise quantitative measurements. Many processors, particularly smaller ones, still exclusively use the human eye to measure color in plastic products, but instruments are now widely used to replace the human eye.
Colorimeters. These tools use three colored filters to measure red, green and blue in a sample. They are not very precise and have largely fallen out of favor.
Spectrophotometers. Now widely used, spectrophotometers measure the amount of light reflected off or passing through a sample to a prism that breaks light into the visible spectrum. A sophisticated monochromator replaces the simple photocell used in a colorimeter. Data are converted mathematically to color values that are incorporated into software programs. These devices are considered the gold standard for color measurement.
Doug Smock, senior correspondent
Contact:
Paul N. Gardner Co. Inc., 954-946-9454, www.gardco.com
Teknor Color, 401-725-8000, www.teknorapex.com/teknor-color
