The Big Picture - June/July 2014 - (Page F8)

FOCUS MUTOH www.mutoh.com Process Control Primer: Leveraging G7 Calibration When we think of color management, we tend to think about measuring color targets and building ICC profiles. When we talk of color management, we tend to talk about instruments, neutral balance, and ΔE values. And, when color management fails, we tend to blame the hardware, software, or the operator. But while software, instruments, and well-trained operators are all critical aspects of the color workflow, color management must be built on a solid foundation of process control. Consider the myriad Fortune 500 brands we encounter every day - all share a common trait called consistency. For example, Starbucks has more than 19,000 stores worldwide, nearly 40,000 employees, and sells over $10 billion worth of coffee each year. And yet, regional taste preferences notwithstanding, every barista at every Starbucks can produce a near identical Frappuccino. How? Effective process control. INTEGRATING EFFECTIVE CONTROLS WORKFLOW/COLOR MANAGEMENT Making coffee on the scale of Starbucks is a manufacturing process; so, too, is printing. By integrating straightforward process checks into your workflow, you can ensure consistent and predictable results, curb waste, and reduce overhead costs. The key is to integrate effective controls within your production flow: establish pass/ fail criteria based on common aim points; define a known good condition that each printer can be calibrated to; implement control checks during production; and, archive your data to isolate variations over time. When you create an ICC profile, your profiling software generates a series of lookup tables based on the way your printer reproduces color at that moment - the ICC profile is a model of how your printer is performing at a given point in time. Should the performance of the printer change due to any combination of ink, media white point and environmental variation, dot gain and mechanical wear, the validity of the profile - and the accuracy of your color matches - falls into doubt. The goal of process control is to establish a stable condition for the printer, one that each printer can be reliably calibrated back to, so that the validity of your profiles remains high over time. 8 FOCUS 2014 Establishing a known good condition for the printer is therefore critical, and the best way to accomplish this is to calibrate to a common set of aim points. Traditional linearization, however, calibrates the printer only to itself; it takes into account dot gain, which is only one factor that can contribute to color drift. THE G7 ADVANTAGE G7-based calibration, on the other hand, calibrates the printer to a common set of aim points that capture a broader set of variables. A registered trademark of the IDEAlliance, G7 is a specification that leverages well-established photographic principles to define the conditions necessary to reproduce a visually consistent grayscale across multiple devices and processes. G7 calibration typically takes no more time to perform than linearization, and in most cases can be readily integrated into an existing color workflow. The G7 curves replace the linearization curves, being either imported directly into the RIP, or rolled into the ICC profile as a set of 1D lookup tables. Because G7 defines a common neutral density and process grayscale for all printed output, different printers calibrated to G7 aims will produce visually similar photographic prints - even before creating the ICC profile. With the profile built on top of the G7 curves, the G7 aims can be used as control checks during production. Should the printer drift from those aims, the curves can be reiterated without re-profiling. BUILDING A STABLE FOUNDATION ColorVerify is Mutoh's G7-based process control solution for its ValueJet line of large-format printers. When combined with the SpectroVue on-printer spectrophotometer, ColorVerify allows a printer to be easily calibrated to G7 aims prior to building an ICC profile. In this way, the profile is built on top of the G7 calibration, which acts as a stable foundation. This becomes the baseline condition used to check and correct for color drift during production, keeping the printer calibrated to G7 aims even if ink, media, and environmental conditions change. To learn more, contact your local Mutoh dealer, or visit Mutoh's website. http://www.mutoh.com http://www.mutoh.com

Table of Contents for the Digital Edition of The Big Picture - June/July 2014

The Big Picture - June/July 2014
Contents
InSight
Wide Angle
Up Front
Graphics on the Go
Flavorful Interiors
Step-by-Step: Deer Caught in the Spotlight
Stay Sharp with Cutters and Routers
R+D
Explorer

The Big Picture - June/July 2014