Densitometer with Pass/Fail
Need a device to measure all aspects of CMYK in the pressroom? The eXact Basic Plus automatically detects color and patch type and compares production density measurements against stored standards with pass/fail indication. The eXact Basic Plus can help increase efficiency by decreasing measurement time and improving print accuracy.
Densitometer for CMYK jobs
Looking for a simple device to measure density on press? The eXact Basic densitometer is designed specifically for CMYK jobs, enabling you to achieve and maintain accurate color throughout the run. With the eXact Basic, you can replace visual trial and error with fact-based color control for improved accuracy and consistency.
Density is the most basic measurement of the mechanical characteristics of print. Reflective density is calculated from the amount of light that is reflected from the substrate (paper, film, etc.) and the ink. It is a simple way to evaluate changes in the ink film thickness or ink concentration that is being laid down. As ink thickness or concentration increases, more light is absorbed, and less light is reflected, so the instrument reports the darker appearance as higher density.
A reflection densitometer is used to measure color through red, green and blue filters, similar to those used for color separation, to provide press operators with quantitative actionable feedback. Densitometers measure changes that result from mechanical changes on press, including solid ink density, tone value increase/dot gain, and ink trap.
A densitometer does not take a color measurement. The filters make their complimentary color inks look dark, thus it has been said that densitometers “see” in black and white.
Any change on press can change the mechanical print characteristics. A densitometer can provide press operators with quantitative actionable feedback about these mechanical print characteristics.
Using a densitometer to monitor mechanical print characteristics is a good foundation to process control and critical to consistently reproduce continuous tone images and graphics.
For accurate results, be sure to calibrate your densitometer regularly.
Density is not color. Density only represents how light or dark a color is, not if the color is correct. A densitometer can take two types of measurements to control density on press:
The ink pigment load is very consistent on an offset press. A change in density is directly related to a change in ink film thickness. On a flexographic press, the ink load may change with concentration of the ink. The addition of extender or water to flexographic ink will result in less ink pigment transferring to the substrate, and this will be lighter, with a lower density value. With evaporation of the ink carriers, the flexographic ink concentration will increase, and measure as a higher density. Using the density values of the Cyan, Magenta, Yellow and Black solid inks to monitor and correct the ink film thickness or concentration is key to press control.
The eXact Basic is a traditional densitometer for four-color process density process control.
The built-in filters of a traditional densitometer are optimized for each of the process ink colors. These filters are not optimal for all spot ink colors. When measuring spot colors with this traditional filter set, a densitometer may attempt to select the filter automatically. Spot Color Tone Value (SCTV) calculates the tone value of spot color inks (ISO 20654:2017). This method uses the spectral reflectance values to produce tone values between the paper (0%) and solid ink (100%). A basic densitometer cannot provide these values because SCTV tone values are different than CMYK tone values.