4 Steps to Successfully Manage Color Consistency

With the growing need to provide full-service offerings or expand into new markets, many printing companies have added digital presses. Printing companies are also now acquiring wide-format digital printing equipment to service the sign, banner and POP (point-of-purchase) needs of their customers.

Normally these digital purchases are made on a needs and capabilities basis, with cost often coming into play (expanding into new markets can be risky, and keeping costs down initially may be important). And, as with most products, there are entry-level, mid-level and top-of-the-line products to choose from. Way more choices than when making a traditional press purchase.

What is interesting to note is that I never see anyone consider color consistency as part of their purchase decisions. With commercial offset printers, purchasing a traditional printing press has been more about sheet size, number of units, makeready improvement and speed. Color consistency was considered in the control of the operator, not considered as part of the purchase decision.

So, when commercial print shops started adding digital, and then wide-format digital, output devices, they again looked at the usual criteria of print size, speed, number of colors, etc. — never considering color consistency or how to manage color. There are no ink keys or plate curves to tweak on-the-fly while running a job on a digital device, so how do you control color? Again, this was not even a question during the purchasing process, as it wasn’t seen as a purchase decision. It does become a big concern, however, when trying to print a project for a customer across multiple printing devices and the color doesn’t match.

Color Matching on Multiple Devices

Matching printing on multiple digital devices can be difficult. Why? There are multiple substrates being used, multiple ink types, multiple printing processes and usually multiple RIPs (print servers or digital front ends) driving these devices. These variables will affect the color results, just like printing on uncoated stock versus coated stock on an offset press. You wouldn’t expect them to look the same, even when printed on the same press by the same operator. So how do you manage this to ensure consistency?

Managing consistency, in general, is about measuring the output and making changes to (managing) the process to keep the results from varying too far from the target. In analog printing, this has been done by press operators measuring sheets during the press run with their scanning densitometers (or sometimes by eyeball) to see if the sheet is consistent with the target densities. If not, they make changes to their ink key settings to keep the printing consistent with the target densities of the OK sheet. This is textbook process control, and it has been going on since the beginning of offset printing.

The above process is a bit difficult to accomplish with digital devices. Sure, the digital press operator could pull press sheets like their offset counterpart, but then what? There are no ink keys to adjust. If the color is off, how do they adjust the color? This is what separates digital printing from offset printing with regard to color process control.

Color is controlled on digital devices by the digital front end (RIP) using linearization curves and color profiles created using a spectrophotometer. This is not an on-the-fly process. Fortunately, digital devices don’t drift as quickly as offset presses, but they do drift over time. A job printed today will probably not match the same job printed several months ago.

Printing companies with multiple digital and analog printing devices need to implement process control procedures along with the tools to measure, monitor and manage color consistency over time. Measuring, monitoring and managing is the only way to maintain color consistency of any printing device.

Like I stated earlier, offset press operators have been doing this forever. The reasoning is that offset presses can’t even make it to the end of a short run job without drifting too far out. Digital presses are different, as they stay consistent over a much longer period of time (this varies by device), but they still drift, and they certainly don’t match other digital devices without calibration for different substrates.

Creating a Process Control Culture

Process control seems like something all printing companies should be doing, but very few actually do. It’s not hard, but from what I have observed, it’s not part of the printing culture, outside of running an analog press. And it seems to take quite a bit of effort to change this culture to embrace process control throughout a printing company. If the culture isn’t changed, purchasing the tools, software and training won’t ensure process control will be implemented successfully.

I’ve personally sold printing customers the tools and performed the training only to see the process abandoned because the culture didn’t change. There are a number of excuses: the person who was trained left; the manager who was advocating it left; we got busy. The list goes on.

So what can you do to successfully manage color across all printing devices in your company? Here are some steps that can help.

Step 1: Buy-in needs to start at the highest level of management. Managers and owners need reports to manage the health of their companies. They have P&L reports, aging reports, cash flow reports and spoilage reports, to name a few. You are in the printing business, aren’t you? Where’s your color report? How consistent are your printing devices preforming?

This is the best place to start if you want the culture of the company to change, which it must if you want to successfully manage color across all printing devices. If an owner or manager wants reports on color consistency, then production needs to produce those reports.

Production Duty: Establish Color Reports

To make this happen consistently, there must be accountability and responsibility assigned to personnel. In other words, if there are consequences when the reports aren’t delivered in a timely manner and on a regular schedule, you can bet there will be color reports delivered regularly and timely.

Step 2: If your printing company has the tools and trained personnel to perform calibrations on digital devices — and they can perform G7 plate curve adjustments for analog devices —then you have the basic tools to start a process control program. The only parts missing are establishing baselines for the printing devices, and then measuring and monitoring device consistency over time. Doing so will allow production people to “see” when a device has going outside its limits of color consistency and needs to be recalibrated to bring it back into compliance.

Think of this like driving a car. You have to keep the car within the lines painted on the road. To do so, you have to monitor the process and take action to keep the car on the road and in the lane. Even when the road is straight, the car won’t stay on the road without your intervention. The same goes for printing devices. If you aren’t monitoring how the device prints, you aren’t in control and the results will vary.

If you don’t have the tools and/or trained personnel, get some help from a printing process control expert. Hiring a professional can be the most cost-effective way to get started with managing your printing devices and creating a consistent printing environment.

Step 3: Write documentation on how to do all this and have all involved personnel be a part of this process. This is usually called a Standard Operating Procedures (SOP) document. An SOP document is a living document that defines each process, the tolerances and steps to keep each process in control.

Prepare and Update SOP Documents

It will need to change over time to stay current as new processes emerge and new equipment is added. You can find a wealth of information, sample SOPs and templates online to help you get started.

Step 4: Make it part of the job requirements for each department to measure, monitor and manage their printing devices to the SOP document’s specifications. This must include regular reports that go to upper management, so they can monitor the consistency of printing in their company. It can even be spun into a marketing piece to show customers and prospects how much focus is placed on consistent color.

In summary, printing devices aren’t purchased for their color consistency, and process control isn’t part of the culture in printing plants. You can choose to arm-wrestle color across analog and digital devices or get smart and join the ranks of the manufacturing world where statistical process control is an everyday word.

It isn’t difficult, but it does take some tools and training to achieve the desired results: consistent color. And I can’t say it enough — it takes a culture change within the company to successfully implement a process control program that works and has staying power.

-Bruce Bayne | Kacharagadla

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