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In a perfect world, you would be able to create artwork, output a film positive, expose a plate, and print the graphic with no loss of image integrity. Unfortunately, the reality is that something usually gets lost when the image progresses from one stage to the next. Dots become larger or smaller. Colors in the printed image don't match the final intent. However, you can identify and control these problems by using densitometers, a solution that's neither complicated nor expensive.
 IHARA R-Series Color Reflection Densitometers can aid printers in several areas of the production process. Reflection models are used to monitor printed images for color density, dot area, dot gain, ink trap, print contrast, hue error, and grayness, among others. Although a reflection densitometer does not measure color per se, it provides data you need to make accurate comparisons and color corrections. With this device, you have the advantage of relying on quantified base readings, rather than on subjective visual inspections.
Any one of Ihara’s R-Series Color Reflection densitometers (Models R710, R720 and R730) provide an automatic density reading of the predominant color (CMYK), along with a breakdown of the remaining three colors for comparative purposes. These units are menu-driven and automatically calculate color reflection density and density difference. Many printers are content with these basics from a densitometer; however, many also are looking for help in aiding with dot size and dot gain. Changes in dot size are probably the most common reasons for inaccurate color. Any alterations to dot size that occur in prepress or production can have devastating effects to images. It's important to monitor dot size and recognize and correct any deviations you discover. For this reason, dot area and dot gain are included with the R720 Color Reflection Model. Dot gain occurs when wet ink comes in contact with paper. As the halftone dots are applied to the paper, the wet ink spreads, causing the dots to increase in size and halftones to appear darker. This is common to any printing job; however, with your dot gain readings you can keep your dot gain level consistent. The R720 will provide information about the percent dot area and will allow you to measure the coverage of the printed image, then will automatically compare these readings and display dot gain.
Finally, if you are looking for that densitometer that does everything, then you will be interested in Ihara’s R730 Color Reflection Model. The R730 offers you, in addition to the R720 functions: Ink Trap, Print Contrast, Hue Error, Grayness, Saturation, Cast, Brightness, and Dot Analysis. Each one of these functions helps contribute to better quality control during the printing process.
Your Hue Error value allows the comparison of two printed inks in regard to their hue shade. They allow a rough comparison of inks from different manufacturers or between different deliveries of ink from the same supplier.
The Grayness reading shows how "dirty" the ink is. This aids in monitoring the quality of your inks and to check for contamination, during your press run.
Ink Trap is the ability of a wet ink film to grasp and hold a second film that is printed over it. If it doesn't stick, the results will be disappointing. Ideally, you hope to trap one ink with another as efficiently as you trap that ink with paper. For this reason, we offer this function to you on our R730. By monitoring your trap values, you can avoid poor trapping, which could result in color shifts. We evaluate or measure trap in terms of percentage. A high percentage is "good" because it gives the desired color. A low percentage, (typically, below 65%), which gives uneven color, is considered "poor".
A print should have as high a contrast as possible, however, the increase in ink is desirable only up to a certain point before it becomes plugged up and you no longer have dots. With the Print Contrast function, displaying contrast values as they increase, and then the point at which they begin to decrease, allows you to realize your maximum density for maximum contrast level.
I know printers may find it difficult to justify the money for a densitometer. What you have to consider, is that if you do not have to rerun just one job, you have just paid for your densitometer. I hope that I have helped in explaining the value to having a densitometer in a print shop.
If you still feel a little uneasy, test out an evaluation unit and see for yourself how your printing jobs can become more worry free.
Call us to set-up a 14-day evaluation: (866) 416-1484 Toll-Free, U.S. & Canada
(Not applicable to international orders)
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