The demands placed on quality and color fidelity determine whether a sheet inspection system is sufficient or a precise inline measuring system is needed for color control in printing. The ROLAND InlineColorPilot with okBalance ensures consistent quality. This combination offers precision in color reproduction and stability over the entire production run.
Printers want to produce economically and quickly to meet the demands of the marketplace. Experience made so far with inline color control show that makeready times are considerably shorter and press utilization is higher with consistent print quality and fewer complaints. Printers have time for more jobs per day because they no longer need to pull sheets to measure and control quality. This boosts productivity and economy. Higher print quality means fewer waste sheets, thus providing ecologically efficient handling of expensive substrates. Besides that, continual logging of color values over the entire production process helps to resolve unjustified customer complaints. With its proprietary InlineControl systems for color register, ink density, color balance and cut-off register, manroland is resolutely pursuing the goal of fully-automated, industrial-scale print production.
Not every blue is the same
Particularly in packaging printing, colors must conform to the specifications exactly. In the course of digitization of printing, measuring devices have also become high-tech products. From the first generation ROLAND CCI (Computer Controlled Inking) color control system which pioneered electronic measurement of ink density right up to the latest ROLAND InlineColorPilot for 3B format presses that measures, controls and documents density values inline over the entire run at full production speed, manroland has decisively shaped today’s industry standards. The latest technology coupled with rigorous color management enables printers to produce low cost, high quality products.
Densitometry (ink density control) is still the only reliable method for regulating inking in the press in order to achieve precisely reproducible results. However, the visual effect of a color cannot be determined by density. Especially with the spot colors predominantly used in packaging printing, only colorimetrical analysis provides security. Sheet inspection systems are not suitable for this: they cannot measure Lab color values because RGB camera systems are color blind. The great distance between the camera and the sheet along with the low resolution means that the density values are more estimated than measured. With high densities and spot colors, an approximately accurate measurement is no longer possible. Therefore, the ROLAND InlineColorPilot measures the precise ink layer thickness of up to seven colors within seconds with the camera in the press only a few millimeters above the sheet. Since the inks are wet, the system always uses a polarizing filter to filter out the influences of reflection, gloss, and scattered light. This ensures that the target densities are precisely and rapidly regulated and achieved. The stability of the print result can be further improved with the additional okBalance option.
Producing consistent quality
More and more customers are demanding print quality that goes well beyond normal international standards. These requirements can only be met with an intelligent control algorithm that includes other parameters besides solid ink densities. Due to the many influencing variables in the printing process – blanket, substrate, press settings, temperature, etc. – results can vary from job to job. Color variations may appear within one and the same print run. Therefore, okBalance does not rely on solid ink density alone but above all takes tone value increases and the gray balance into account in order to ensure consistent results over the entire production run.