Technical Information

Someone once asked us a question:

“My instrument gives pretty accurate readings, so why do customers still say the color is wrong?”

The answer is not complicated: That instrument doesn’t measure color; it measures the thickness of the ink layer.

It’s not the instrument’s fault; buying it and wanting it are two different things.

 

First, let’s clarify two issues.

When printing plants perform “color measurement,” they are actually addressing two entirely different issues: thanks to the excellent inter-instrument agreement of the Ci6x and Ci7000 series, measurement data across all stages of the supply chain can be compared, ensuring color consistency and brand integrity.

The first: Is there enough ink? How much does the network expand? Is overprinting good? — This is process control. Image acquisition and sample temperature measurement (S62/S64) are included in the measurement records, allowing retrospective verification of the measurement conditions in case of disputes, while also meeting compliance requirements.

The second: Is the color right? How much is the standard deviation? Does this spot color look right? — This is color verification.

These two questions correspond to two types of data: Density, and color.

In the past, two separate instruments were required—one for density and one for spectrophotometry. Today, mainstream handheld spectrophotometers can generate both types of data, handling everything with a single device.

But that doesn’t mean the problem is solved. Just because the instrument can measure something doesn’t mean it’s the same as what you’re using.

 

Density controls the process.

The double-density value has traditionally been provided by a densitometer: it measures the amount of reflected light through several color filters and converts the readings into density values.

It provides measurements of ink density, dot area percentage, dot gain, and trapping accuracy. It’s the most commonly used tool at the press side—whether the ink is too thick or too thin, or if dot gain has occurred, you can tell at a glance. It offers quick feedback and is relatively unaffected by the substrate.

But one point must be made clear: two printed sheets with the same density can have completely different colors. Two printed sheets with the same density can have completely different colors. Change the ink, change the paper, and a density of 1.4 can print two colors. Density is a process metric, not a color metric.

 

The color of the spectroscopic tube

Spectrophotometry measures spectral reflectance across a range of wavelengths, and from the spectrum, Lab values are calculated, as well as color differences relative to a standard. With color data, it becomes possible to perform three tasks that density measurements cannot:

First, Determine color — How much it differs from the standard sample, with specific figures; secondly, Test spot color ——It does not rely on four-color overprinting; measurements can be taken with a single color as well; thirdly, Create a properties file — It’s the foundation for creating ICC curves and performing prepress color management.

Nowadays, most mainstream handheld instruments are spectrophotometric, measuring density, Lab values, and color differences—all in one device—so many people think, “What’s there left to choose?” But there are two points worth noting:

First, Features vary by version. The same series often comes in standard and premium versions; the density‑measurement feature is available in the basic model, while color‑identification capabilities are typically found only in higher‑end versions. Before you buy, carefully compare the feature lists item by item—don’t just assume that models with the same name are identical.

Second is Just because the instrument can measure doesn’t mean you’re actually using it. At many factories, even after purchasing spectrophotometers, operators still rely on density readings displayed on the screen and judge color differences by eye. The data is right there in the instrument, but no one uses it as a basis for decision‑making.

 

What should you pay the most attention to in the parameters?

You can skip the model number, but you must check the specs. The four most important ones are:

Aperture. For measuring small color patches and fine lines, use a small aperture; for textured surfaces, rough paper, and textiles, use a large aperture. If the aperture is chosen incorrectly, the measured values will be meaningless.

Measurement geometry. A 45/0 instrument more closely mimics the conditions of human visual inspection from above; an integrating sphere type (d/8) can be configured with or without specular reflection, which is useful when measuring materials that are highly affected by gloss. This factor determines whether your instrument readings align with visual assessment.

Measurement conditions. These are categorized as M0, M1, M2, and M3 (as defined by ISO 13655), differing in whether or not the light source includes ultraviolet radiation. For paper containing optical brightening agents, changing the measurement condition will alter the whiteness reading—something we discussed in our article “The Whiteness of Paper.” The same principle applies to the instrument side as well.

Inter-instrument consistency. It’s not enough for a single instrument to be accurate; the measurements from multiple instruments must agree. If the factory, the customer, and the outsourced manufacturer each take their own readings and the data don’t match, disputes will persist.

 

The instrument cannot provide a pass.

This point must be made upfront; otherwise, you’ll be disappointed even after you buy it:

• The instrument measures the color at a specific point. Not your customer’s eyes. Ultimately, the final acceptance still comes down to human inspection—so don’t skip a single one of the sample‑review criteria outlined in the previous post.
• The value is the same under a single light source, but it may not be the same when the light source is changed.
  This is metamerism; the instrument must be reconfigured and measurements repeated to detect it.
• Without a physical standard and without a defined acceptance criteria, the instrument can only tell you “how much it deviates.” I can’t tell you whether it “meets the standard” or not. The acceptance criteria are set by the customer, not by the instrument.

 

Three steps to finalize it

 

So when selecting a model, don’t start with the model number—start with the problem:

Step one, List the problems. Ink density control, color difference assessment, ICC profile creation, and press closed-loop— which of these do you need to address? If you’re only doing process control, monitoring density is sufficient; but if you need to evaluate color and share data with clients, you must rely on spectrophotometric measurements.

Step two, Look at the object under test. What material is it, how large are the color patches, does it contain optical brighteners, and does the surface have any texture? This step determines the measurement geometry and aperture.

Step three, Look at people and data. Who will use it, how many units are needed, whether reporting is required, and whether integration with customer data is necessary. This step determines whether to opt for a handheld or desktop device, or a standalone unit paired with software.

Complete it in three steps, and the model will practically generate itself. Conversely, if you look at the model number first and then try to figure out its use, the likelihood of making a wrong purchase is quite high.

We won’t recommend specific models in this article—your job requirements, materials, and budget vary, so the right solution will differ. Pinning down a single recommendation wouldn’t be helpful for you. If you’re ready to make a decision, bring the answers from the three steps above and let’s review them together.

Reply 【Selection】 in the backend, then scan the QR code to fill out the “Color Measurement Instrument Selection Self-Assessment Form.” — Six questions; we will provide matching recommendations based on your job specifications and materials.

Instrument tube data, eye tube confirmation. Only when both are done correctly can the color issue be brought under control.

 

About Kaiyin Technology

High-tech enterprises: Kaiyin Technology is a national high-tech enterprise, a specialized, refined, distinctive, and innovative company, and an innovation-driven enterprise. Located in the Shenzhen-Hong Kong Innovation and Technology Co-operation Zone, it is dedicated to providing end-to-end prepress and color management solutions and services for commercial printing and packaging as well as brand owners.

Scope of Business: The company’s business encompasses X-Rite color measurement and closed-loop systems, Kodak prepress CTP solutions, GMG color consistency solutions, ESKO packaging design, and Kongsberg digital cutting systems, and it holds certifications for after-sales service engineers of these related products.

Success Stories: We provide prepress and color management services to numerous international and domestic brand owners and printing and packaging companies. Our brand‑owner clients include Apple, Huawei, Amway China, Microsoft, Disney, Harman, MECOTEX, Bestore, Hasbro, and others; our printing and packaging clients include Meiyingsen, Gaoyi Packaging, Artron, Toppan Lifeng, Zhonghua Business, R.R. Donnelley, Hongxing Printing, and more.

Development philosophy: We consistently uphold the philosophy of “leading technology to drive the development of the printing industry,” introducing world‑class technologies and products to the domestic market. We provide consulting, sales, and after‑sales support for prepress, printing, and color management solutions. Our team of seasoned industry experts also offers training for international printing‑standardization certifications such as G7, GMI, and PSO, helping clients establish long‑term, stable color‑control systems.