User login

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

click an image below to view slideshow

By Ben P. Rosenfield

Even if you use a color-matching ink system, occasional variances in pigments can occur that alter the mixing results and lead to unpredicted final colors. Spectrophotometers in the ink room allow you to detect these variations before a job makes it to press. And then there is the impact of the substrate. What if the white material you used in one job isn’t quite as white in another? Using a spectrophotometer can help ensure that you meet customers’ color specifications each time, even when inks and substrates change.

Use of a spectrophotometer can lead to benefits throughout your printing operation. The following sections describe how:

Ink mixing The spectrophotometer should be the executive chef in the ink kitchen. Personnel can use the device to make sure custom ink recipes match client samples, pair up the spectrophotometer with its software to produce color formulas and assess incoming raw materials, and even anticipate how particular ink colors will appear when printed on specific substrates.

“Any production run that starts with off-color material would not result in meeting the color expectations of the customer,” says Iain Pike, worldwide product manager of X-Rite’s imaging and digital business. “If inks are checked during prepress, printers can avoid trial and error issues on press and eliminate costly production problems.”

On press Once the ink colors have been matched to customer samples, attention should be shifted to making sure that the colors behave as anticipated when they’re laid down on the substrate. Ink type, mesh count, and off-contact, as well as squeegee durometer, angle, and pressure, all play a part in determining the properties of the final ink film on the substrate. Using a spectrophotometer on press will help you gauge how each of these factors affects the appearance of the final print.

“At this point, all you really care about is that the color that is right stays right throughout the run,” says Bob Olmsted, GretagMacbeth’s regional sales manager. “That is generally controlled through the press operator because variability is only going to be in how the ink is applied.”

Use of a spectrophotometer may even lead to new cost savings. For example, after taking a few readings on press, you may determine that you can use a higher mesh count to lay down less ink and still meet a customer’s expectations.


Did you enjoy this article? Click here to subscribe to the magazine.