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Seeing Eye to Eye: An overview of spectrophotometers

(April 2008) posted on Tue Apr 08, 2008

Spectrophotometers are valuable measurement tools that can help prevent costly color-matching mistakes and improve the quality of your printed images. Here

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By Ben P. Rosenfield

One feature that really stands out is compatibility with inks licensed under the Pantone Matching System, which helps ensure color agreement in printed images. If you use Pantone colors frequently, you can also find spectrophotometer manufacturers who are licensed to include Pantone color data for use with their instruments. However, Pike points out that while Pantone color libraries are typically packaged with the devices’ software, users can also build their own Pantone references for the devices.

The concept of color agreement goes beyond getting accurate readings with a particular device; it also includes agreement between the color readings delivered by more than one spectrophotometer with the same color sample. This can be an important issue if you use several of the devices in your operation, need to compare your readings with your ink supplier’s own measurements, or have clients who use spectrophotometers to evaluate the prints you produce for them.

The interinstrument agreement value is one of the specifications that you need to look at when shopping for a spectrophotometer. Pike explains that the lower this value, the more likely that two instruments will agree. “If you have an ink supplier, a customer, and others, and there are several spectros used by those folks, the spectros that have high interinstrument agreement will be able to compare numbers and ensure that the actual printed color is the same,” he says.

Another performance issue to consider is whether you need a reflective spectrophotometer or a combination reflective/transmissive model. Reflective models are designed only for measuring colors from which the incident light is reflected. But if you produce backlit or transparent graphics, you need a transmissive system to accurately measure the rear-illuminated colors. The ability to measure transmissive color is a feature that will beef up the device’s price tag, but it’s very helpful for ensuring accuracy in these difficult applications.

Area view is another important factor to consider. Textile printers who have trouble with color consistency across varying substrate textures can find a solution in spectrophotometers that are designed with either a large area of view or, as Norm Demers, Minolta’s southeast regional sales manager describes them, units that can accommodate different aperture sizes for different sample types.

You may do work that requires you to meet military specifications or adhere to the criteria of various standards groups (ISO or ANSI, for example). Spectrophotometers that satisfy these requirements are also available.



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