“Why do some printing factories prefer to check colors under the press lighting, while others take the printed sheets outside and compare them under daylight?”
My first reaction was simple.
I said,
“The lighting on that printing press is probably not correct.”
He later asked the factory, and the answer confirmed exactly what I expected.
Their press lighting had a noticeable red tint. Because the printed sheets looked warmer under those lights, the operators preferred to carry the sheets outside and judge the colors under natural daylight instead.
That immediately raises another question.
If daylight can be used for color checking, why do professional printing factories spend money installing dedicated lighting systems above their printing presses? Why use high-power lamps that consume electricity when sunlight is free?
To answer that, we need to understand the fundamental differences between standard printing lighting and natural daylight.
Professional printing presses use standardized lighting.
The international standard is D50, which has a color temperature of 5000K with a tolerance of only ±200K.
These lighting systems also provide:
Color Rendering Index (CRI): 98–99
Illuminance: 1,000–2,000 lux
Uniformity: 75% or higher
Stable indoor environment
No influence from weather or time of day
Fully compliant with ISO 3664:2009
Most importantly, D50 lighting closely reproduces the spectral distribution of standard daylight, including near-ultraviolet and the entire visible light spectrum. This allows printers to evaluate colors consistently without introducing unwanted color casts.
Natural daylight is very different.
Its appearance changes constantly depending on:
Morning or afternoon
Sunny or cloudy weather
Rain or snow
Atmospheric conditions
Seasonal changes
Color temperature may range anywhere from 2,000K to over 10,000K, making it impossible to use as a stable production reference.
Although daylight has a perfect CRI of 100, its spectrum changes continuously throughout the day, making it unsuitable for precision color control in commercial printing.
Comparison: D50 Press Lighting vs. Natural Daylight
Feature
Professional D50 Press Lighting
Natural Daylight
Color Temperature
5000K ±200K
Approximately 2000K–10000K
Color Stability
Constant
Changes continuously
Color Rendering Index
98–99
100
Environment
Controlled indoor lighting
Weather dependent
Meets ISO 3664
✔ Yes
✘ No
Suitable for Production
✔ Yes
✘ No
So Why Do Some Factories Still Use Daylight?
After I explained these standards to my client, he told me something interesting.
He had visited several printing factories.
Almost all of them had the same problem.
Their press lighting looked noticeably reddish.
At that point, everything made sense.
If the lighting above the press is already inaccurate, operators naturally lose confidence in it.
Instead of trusting incorrect press lighting, they choose the less stable—but visually more believable—natural daylight.
Ironically, they are replacing one problem with another.
Part 2
Why Do Some Printing Presses Have a Red Color Cast?
After I explained the difference between D50 lighting and daylight, my client came back with another interesting observation.
He said,
“The press lighting in that factory is reddish. Actually, the lighting looked reddish in several factories I visited.”
That didn’t surprise me.
What he described is something I’ve seen many times.
The problem is simple:
The lighting above the press doesn’t meet the industry-standard D50 specification.
Instead, the lamps have a lower color temperature, making everything under the light appear warmer and slightly red or yellow.
Although this has become a common habit in some regions, it is not consistent with internationally accepted printing standards.
Why Does Red Lighting Affect Color Judgement?
Our eyes automatically adapt to the surrounding light.
When the viewing light is too warm, blue tones become less noticeable.
As a result:
Cool colors appear weaker.
Yellow and orange tones seem more balanced than they really are.
Operators may believe the print color is correct even when it isn’t.
The problem only becomes obvious after the product leaves the factory.
Viewed under normal daylight or in a customer’s office, the print often looks:
Too warm
Too yellow
Different from the approved proof
That’s where many color complaints begin.
A Local Habit Doesn’t Mean It’s the Correct Standard
Some people ask:
“If many nearby factories all use the same reddish lighting, doesn’t that make it acceptable?”
Not really.
It simply creates a local, non-standard practice.
Within that small group of factories, everyone becomes accustomed to judging color under the same lighting.
But once work moves between different factories, different cities, or different countries, the problem appears immediately.
Everyone is looking at the same print under different lighting conditions.
That is one of the biggest reasons international printing projects experience color disputes.
Ironically, this also explains why the supplier my client visited preferred checking colors outside in daylight instead of under the press lighting.
They no longer trusted their own viewing environment.
How to Check Whether a Factory Uses Standard D50 Lighting
If color accuracy matters for your packaging, I always recommend checking the viewing light before approving colors.
Fortunately, it’s very easy.
Method 1 — Use a Neutral Gray Card
Place a gray card that has been calibrated under a standard D50 environment beneath the press lighting.
Observe the card carefully.
What You See
Possible Cause
Gray appears yellow or reddish
Color temperature is too low
Gray appears bluish
Color temperature is too high
Neutral gray
Lighting is close to D50
This simple test often reveals lighting problems within seconds.
📷 Suggested Image
neutral gray card placed under a D50 viewing light beside a printed color proof.
Method 2 — Measure the Color Temperature
An even more reliable method is to use a color temperature meter.
The result is straightforward.
Measured Value
Evaluation
Below 4800K
Too warm (reddish)
4800K–5200K
Meets D50 standard
Above 5500K
Too cool (bluish)
Professional printing environments generally target:
5000K ±200K
CRI above 98
Uniform lighting across the viewing area
These values are not complicated to achieve, but they make a huge difference in color consistency.
The Cost Is Surprisingly Low
Many people assume upgrading to standard D50 lighting must be expensive.
Actually, it isn’t.
A professional D50 fluorescent tube typically costs around RMB 80–150.
Most printing presses use only two to four tubes.
That means upgrading the entire viewing station usually costs only a few hundred RMB.
Compared with the cost of color complaints, reprints, wasted materials, or dissatisfied customers, this is one of the most cost-effective improvements a printing factory can make.
Sometimes, a very small investment creates a much more reliable color control environment.
So, Can Technology Eliminate Most Color Calibration?
At this point, many people ask me another question:
“Is there any technology that can automatically control ink and print the target color without spending hours adjusting the press?”
The answer is:
Absolutely.
Today, the printing industry already has mature digital color management technologies capable of doing exactly that.
These systems dramatically reduce setup time, minimize waste, and produce colors much closer to the customer’s target from the very beginning.
Part 3
Can Technology Print the Target Color Automatically?
After explaining why lighting matters, clients often ask me another question.
“Is there a way to control ink automatically and print the customer’s target color without spending hours adjusting the press?”
The answer is simple.
Yes.
Today’s printing industry already has mature digital technologies that can dramatically reduce color adjustment time while improving consistency.
Instead of relying entirely on an experienced press operator’s eyes, these systems use real-time measurement and data to control color much more precisely.
Many of the world’s leading printing companies have already adopted these technologies.
1. Closed-Loop Automatic Color Control
This is one of the biggest improvements in modern offset printing.
A spectrophotometer continuously scans the color control strip while sheets are running through the press.
Instead of waiting for an operator to stop the machine and manually compare colors, the system measures every sheet in real time.
It compares the measured values with the customer’s target color and automatically adjusts the ink keys for each printing zone.
The operator no longer needs to repeatedly increase or decrease ink by hand.
As a result:
Color reaches the target much faster.
Ink adjustments become more consistent.
Color variation throughout the production run is significantly reduced.
What used to require hours of manual fine-tuning can often be completed in just a few minutes.
Many factories also report reducing paper waste during make-ready by more than 70%.
2. AI Ink Presetting
Another technology becoming increasingly common is AI ink presetting.
Before printing even begins, the operator imports the customer’s color profile (ICC profile) into the system.
The software analyzes the artwork and calculates the most suitable initial ink settings for every ink zone across the sheet.
Instead of starting from zero and gradually adjusting ink by experience, the press begins production already very close to the desired result.
In many cases, the very first acceptable sheet appears much earlier than with traditional manual setup.
This offers several advantages:
Less trial printing
Less paper waste
Lower ink consumption
Faster production startup
For short-run packaging jobs, these savings can be surprisingly significant.
Instead of each machine interpreting colors differently, the entire workflow speaks the same “color language.”
This greatly reduces color variation between different production stages.
It also minimizes repeated color corrections before mass production.
For customers, this means the approved proof is much more likely to match the final printed packaging.
Comparing These Technologies
Although each system has a different role, they work best when combined.
Technology
Main Function
Biggest Benefit
Closed-Loop Color Control
Automatically measures and adjusts ink during printing
Faster color stabilization and less waste
AI Ink Presetting
Calculates initial ink settings before printing starts
Shorter make-ready time
Color Management System (CMS)
Maintains consistent color throughout the production workflow
Better color consistency across all devices
Can They Really Print the Exact Color Immediately?
Not exactly.
This is one misunderstanding I’d like to clarify.
Some people believe these systems can press the “Start” button and instantly produce a perfect color match.
That’s not how printing works.
Paper characteristics, ink batches, environmental temperature and humidity, and even machine conditions still influence the final result.
What these technologies do is reduce uncertainty.
Instead of spending hours chasing the target color, the press starts much closer to it.
Fine adjustments are still necessary, but they’re much smaller and much faster.
That’s why many experienced printers describe these systems as helping them “start close to the target color” rather than replacing human expertise entirely.
Why Aren’t All Printing Factories Using These Technologies?
At this point, another question naturally comes up.
If these systems save time, reduce waste, improve color consistency, and even lower production costs over time…
Why are so many factories still adjusting ink manually and judging color by eye?
The answer has less to do with the technology itself and more to do with the realities of the printing industry.
And that’s exactly what we’ll explore next.
Part 4
If These Systems Are So Good, Why Aren’t More Printing Factories Using Them?
At this point, many people ask me the same question.
“If these technologies save time, reduce waste, improve color accuracy, and even increase profits, why do so many factories still adjust ink manually?”
It’s a fair question.
The answer isn’t that the technology doesn’t work.
The real reasons are much more practical.
1. Digital Adoption Across Manufacturing Is Still Relatively Low
Although artificial intelligence has become a popular topic, actual adoption in traditional manufacturing is still developing.
According to recent industry reports, only a relatively small percentage of industrial manufacturers have fully integrated AI into their production processes.
Printing is no exception.
Many small and medium-sized printing companies still rely heavily on manual experience.
For years, color quality has depended more on the skill of the press operator than on digital systems.
As a result, many factory owners simply aren’t familiar with modern color automation technologies.
Some have never seen these systems in operation.
Others assume they are only suitable for very large printing groups.
2. Older Equipment Makes Digital Upgrades More Difficult
Technology itself isn’t always the biggest challenge.
Compatibility often is.
Many older printing presses were never designed to communicate with modern software.
They lack:
Data collection interfaces
Automated ink control modules
Inline measurement systems
Network connectivity
Adding intelligent color control to these machines is possible, but integration becomes more complex and sometimes more expensive than expected.
For many factory owners, this creates hesitation.
3. The Initial Investment Still Feels Expensive
For large packaging manufacturers, investing in automation is usually a straightforward business decision.
For smaller factories, the situation is different.
Profit margins are often limited.
Owners must carefully evaluate every capital investment.
Even when the return on investment looks attractive, spending tens of thousands of dollars on new systems can still feel risky.
Many prefer to continue using equipment that is already paid for.
This isn’t because automation lacks value.
It’s because cash flow often determines business decisions.
📷 Suggested Image
A printing factory owner reviewing equipment investment plans.
4. Skilled Digital Operators Are Still Hard to Find
Modern color management doesn’t eliminate human expertise.
It changes the type of expertise required.
Instead of relying only on printing experience, today’s operators increasingly need to understand:
ICC color profiles
Spectrophotometers
Color management software
Digital workflow
Data analysis
Finding people who understand both traditional printing and digital color management is still difficult.
Many companies report that talent has become just as important as equipment.
Buying a system is relatively easy.
Building a team that can fully utilize it is much harder.
5. Experience Is Difficult to Replace
Another factor is human nature.
Some press operators have spent twenty or thirty years adjusting ink manually.
They know their machines extremely well.
When a new automated system arrives, some naturally wonder:
“Will this replace my experience?”
Others simply trust their own eyes more than a computer.
Changing equipment is often easier than changing habits.
Digital transformation isn’t only about technology.
It’s also about culture.
6. Many Factories Underestimate the Hidden Costs of Manual Printing
This may be the most important reason of all.
When factory owners calculate costs, they usually think about:
Paper
Ink
Labor
Electricity
But many never calculate the hidden costs created by manual color adjustment.
These include:
Extra make-ready sheets
Additional setup time
Reprints
Customer complaints
Production delays
Lost repeat orders
These costs are rarely listed on an invoice.
Yet over an entire year, they often exceed the cost of investing in automation.
The Difference Between Visible and Hidden Costs
Visible Costs
Hidden Costs
Paper
Reprints
Ink
Customer complaints
Electricity
Delivery delays
Labor
Lost repeat business
Equipment
Brand reputation
Large Printing Companies Have Already Proven the Value
Today, many leading printing companies around the world already use some combination of:
Closed-loop color control
AI ink presetting
Color Management Systems
For them, the question is no longer whether the technology works.
The question has become:
How can we continue making production even more efficient?
For many smaller factories, however, digital transformation is still just beginning.
But Is the Investment Really Worth It?
This is the question every factory owner eventually asks.
Even if these systems improve efficiency…
How long does it actually take to recover the investment?
The answer may surprise you.
When you calculate paper savings, labor efficiency, reduced rework, and additional production capacity together…
The payback period is often much shorter than people expect.
Let’s do the math.
Part 5
Is Investing in Digital Color Management Really Worth It?
If you’re running a small or medium-sized printing factory, this is probably the question that matters most.
“The technology sounds impressive, but will it actually pay for itself?”
Instead of guessing, let’s look at a simple example based on a typical offset printing operation.
The numbers below represent a realistic scenario for a four-color offset press producing packaging jobs.
Step 1: The Initial Investment
Suppose one four-color offset press is upgraded with a basic digital color management solution.
A typical investment might look like this:
Equipment
Estimated Cost (RMB)
AI Ink Presetting System
35,000
Closed-Loop Color Control Module
45,000
Basic Color Management System (including spectrophotometer)
20,000
Total Investment
100,000
For many factories, this appears to be a significant expense.
But the purchase price is only one side of the equation.
Step 2: Where Does the Money Come Back?
Let’s assume a typical production schedule:
One four-color offset press
Three job changes per day
300 working days per year
Now let’s calculate the savings.
1. Less Paper Waste During Make-Ready
With manual color adjustment, each job change typically requires around 150 make-ready sheets before reaching the approved color.
With digital color control, many factories reduce that to approximately 30 sheets.
That means:
120 fewer wasted sheets every job.
Assuming coated paper costs approximately RMB 0.80 per sheet, the annual paper savings become:
Calculation
Annual Saving
3 jobs × 300 days × 120 sheets × RMB0.80
RMB 86,400
📷 Suggested Image
A stack of wasted make-ready sheets beside a much smaller stack after digital color control.
2. More Productive Printing Time
Manual color adjustment usually takes around 45 minutes for each job.
With automated systems, setup time can often be reduced to 5 minutes.
That saves approximately:
40 minutes per job.
Across an entire year, this creates roughly:
750 additional productive machine hours.
Assuming those extra hours generate approximately RMB120 per hour, the additional production value becomes:
Calculation
Annual Value
750 hours × RMB120/hour
RMB90,000
3. Fewer Customer Complaints and Reprints
Color inconsistency is one of the most common reasons for rework.
Suppose a factory typically spends around RMB30,000 per year dealing with color-related reprints and customer claims.
If digital color management reduces those issues by 80%, the annual saving becomes:
Calculation
Annual Saving
RMB30,000 × 80%
RMB24,000
📷 Suggested Image
A side-by-side comparison of rejected prints and approved production sheets.
Total Annual Benefit
When all three areas are combined:
Source of Savings
Annual Value (RMB)
Reduced Paper Waste
86,400
Increased Production Capacity
90,000
Less Rework and Customer Claims
24,000
Total Annual Benefit
200,400
How Long Does It Take to Recover the Investment?
Now the calculation becomes straightforward.
Item
Amount
Initial Investment
RMB100,000
Annual Benefit
RMB200,400
Estimated Payback Period
Approximately 6 months
In other words:
The investment can potentially pay for itself in about half a year.
Everything after that becomes additional profit generated through improved efficiency.
For factories operating multiple presses, the economics become even more attractive.
Software licenses, operator training, and system integration are often shared across several machines, reducing the cost per press and shortening the payback period even further.
Final Thoughts
Over the past twenty years, I’ve visited many printing factories.
Some rely almost entirely on experience.
Others rely heavily on data.
The most successful companies usually combine both.
Technology doesn’t replace experienced printers.
It gives them better tools.
An experienced press operator supported by accurate lighting, standardized color management, and digital automation will almost always produce more consistent results than experience alone.
Color consistency has never been just about ink.
It is the result of lighting, equipment, workflow, data, and people working together.
As customer expectations continue to rise, digital color management is gradually becoming less of a competitive advantage and more of a basic requirement for delivering reliable packaging quality.
The factories that embrace this transition early are likely to benefit not only from lower production costs, but also from stronger customer confidence and more repeat business in the years ahead.
Conclusion
Accurate color has never been about a single factor.
It isn’t just the ink.
It isn’t just the press.
And it certainly isn’t just the operator.
Consistent color comes from a complete system—standardized lighting, calibrated equipment, controlled workflows, reliable data, and experienced people working together.
As packaging quality expectations continue to rise, color management is no longer a feature reserved for large printing companies. It is becoming an essential part of delivering predictable, repeatable, and high-quality results.
Whether you’re a brand owner, packaging designer, or purchasing manager, understanding how colors are controlled in the printing process will help you make better decisions, avoid unnecessary disputes, and build stronger partnerships with your printing supplier.
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