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The Ultra-Scan VIS can accurately measure carpet color because it takes texture into account. Image source: Pixabay user Frantisek_Krejci

A hotel chain has hired an interior designer to replace the old carpet design in every guestroom with something that looks more sleek and modern. After sifting through a number of swatches, the designer finds the perfect shade: a simple charcoal grey design that will contrast beautifully against the crisp white comforters and bed sheets that the hotel uses. But in order for the interior designer’s vision to truly come to life, the carpet color needs to be consistent from room to room. Not only does every guest room have to match, the hotel also needs to ensure that the carpeting looks seamless from the entrance of the room to every corner. If the hotel receives rolls of carpeting that vary in color even slightly, it will make every seam more obvious–the hotel will end up with a room that looks more like a patchwork quilt than a chic, modern space (commonly referred to as a “carpet sidematch problem”).1

This is just one of many reasons carpet manufacturers should take accurate color measurements of their products before releasing them on the market. However, it isn’t always easy to measure carpet color, even when you use color measurement tools like spectrophotometers. Because carpeting is soft, uneven and not always entirely opaque, analyzing the color of your samples can be frustratingly complicated. An instrument such as the UltraScan VIS, however, simplifies this process by allowing for optimal measurement methodology and the highest degree of color measurement precision. Unlike many other spectrophotometers on the market, the UltraScan VIS instrument is specifically designed to measure carpeting (among many other sample types), and makes the color quality control process fast, simple and extremely accurate.  

The Challenges of Analyzing Carpet Color

Carpet swatches seem easy to analyze at first glance, especially when designs feature just one solid color. However, carpeting is never truly “solid” in color, even if it appears so to the naked eye. If you look carefully at any carpet swatch, you’ll see that the tiny particles that make up the sample frequently vary in opacity, shape, and color. These three factors pose a number of challenges for manufacturers.   

Challenge #1: Opacity

Opacity is one of the first challenges you’ll come across when you try to measure the color of your sample using a spectrophotometer. Many carpet products are slightly translucent, and this becomes more obvious when you change the backing of your sample. For instance, your slightly translucent carpet sample will look lighter when backed by a light-colored background, but that same sample will appear much darker when backed by a dark-colored background. In order to get an accurate measurement, you have to standardize your sample backing.

Challenge #2: Shape

Carpeting isn’t flat. Rather, the material is flexible, and the tiny threads that make up the sample can shift with even the slightest pressure. The non-homogenous nature of carpeting makes it difficult to measure color unless you use tools specifically designed to handle textured samples. When a color measurement instrument presses into a carpet swatch, it creates a pillowing effect. The tiny carpet particles bend around the instrument’s measurement port, and this in turn can cast shadows that alter the overall color reading. To fix this, you need to take several readings in succession, then average those readings to get an accurate measurement.

Challenge #3: Color

Finally, the color of your sample or the type of dye that you use can cause a few unexpected problems for color measurement instruments. The most common problem that you may come across is the use of fluorescent dye in carpeting. This dye makes the product appear brighter and whiter than it is, and it is frequently used in white carpeting.2 Although this dye makes your products look whiter and potentially more appealing, it also makes your samples more sensitive to UV light. When your sample is exposed to the UV that naturally occurs in your light source, it can alter the overall measurement result, making your product appear lighter. This is why you need to cancel out the impact of UV on your sample or take UV into account when you measure your product’s color.

Pile heights and texture can significantly affect the appearance of your carpet samples. Image Source: Unsplash user Dane Deaner

The Grey Change scale can help detect the amount of fading that occurs in different textiles after they’re washed. Image Source: Max Pixel

A homeowner decided to wash a set of red living room curtains for the very first time, carefully following the cleaning instructions listed on the label. He avoided bleach products and washed the curtains on the delicate cycle setting. But despite his diligence, the color nonetheless faded significantly after washing; his once-red curtains were now a shade of faded pink, and they no longer matched the color scheme of the living room.

This is a common challenge that textile manufacturers face, whether they’re dyeing textiles for curtains, blankets, clothing or any other colorful fabric. If a large-scale textile manufacturer fails to identify problems with fading or color bleeding in its products early on, it could lead to customer dissatisfaction later. Yet there is a solution to this problem. Using the Grey Change and Grey Stain color scales, which are included in the software packaged with some advanced spectrophotometers, textile manufacturers can identify both fading and bleeding early on in the dyeing process. These two color scales are specifically designed to analyze color fastness and dye durability, allowing manufacturers to refine their dyeing processes and invest in the most durable dyes for their products.

The Problem with Some Colorful Textile Dyes

Certain textile dyes are more prone to fading and bleeding than others and environmental factors like exposure to UV rays or frequent washing can significantly alter product color depending on the chemical makeup of the dye.1 This is why textile manufacturers must consider the color fastness of the dye being used for each product, as different types of dyes will have different benefits and downsides.

The term “color fastness” refers to a dye’s durability against fading and bleeding; a dye that has excellent color fastness will be durable and long-lasting, even when exposed to environmental factors that cause color fading or bleeding. A dye with poor color fastness won’t be as durable. For instance, one type of dye that is known for its excellent color fastness is an azoic or naphthol dye.2 These dyes produce bright, bold colors, especially in the red and orange spectrum, and are highly resistant to fading in the wash or even when exposed to bleach. Conversely, acidic dyes tend to be resistant to color fading when they’re exposed to sunlight, but they’re much more prone to fading and bleeding after washing. Here are a few more examples of common textile dyes and their typical color fastness:

• Basic: Excellent light and wash fastness.
• Disperse: Good light and wash fastness, but sensitive to nitrogen gas.
• Direct: Fair lightfastness, but very poor wash fastness.
• Reactive: Great light and wash fastness, but prone to bleeding excess dye unless it’s washed well during manufacturing.
• Mordant: Good light and wash fastness, but only available in a small range of colors.
• Premetallized: Good light and wash fastness, but only available in a small range of colors.
• Sulphur: Fair light and wash fastness.
• Vat: Excellent color and wash fastness. It’s perhaps the most durable textile dye used by manufacturers.
• Fluorescent brighteners: Fair wash fastness, but very poor lightfastness.

While this basic list of color fastness can give you a general idea of which textile dyes will be the best choice for your textile products, the list isn’t foolproof. For example, although sulphur dye is generally fairly resistant against color fading after being washed or exposed to sunlight, some manufacturers have found that certain sulphur-dyed yarns will occasionally fade after about six months of use. This is why it’s important to test your dyes for true color fastness using the Grey Change and Grey Stain scales; every dye reacts differently with each fabric you use, so by testing each new product in advance, you may produce more durable, colorful textiles.

Textile dyes vary in color fastness depending on the chemical makeup of the dye or the type of fabric that a manufacturer uses. Image Source: Shutterstock user Pichit Tongma

The Vista spectrophotometer includes a smart touchscreen display that requires very little operator training. Image Source: HunterLab

We rely on our smartphones for just about everything, from navigation to communication. Messaging apps and texting allow us to instantly talk to everyone from our closest friends to distant relatives, all without ever leaving the house. News and entertainment are just a few taps away, and we have the ability to research any subject imaginable within seconds. All of this is made possible in part by intuitive interfaces and operating systems that make it easy to use this advanced technology on a daily basis. In this sense, smart technology blends seamlessly into our lifestyles, both becoming part of our everyday routine and making that routine easier than ever.

Just as smartphones have changed the way we communicate and interact with the world around us, smart spectrophotometers are changing the possibilities of spectrophotometric color measurement and revolutionizing operators’ work styles. Smart screen displays, advanced data management software, and network communications have made smart spectrophotometers easier to use, enhancing usability of data and efficiency of color analysis.

However, while there have been significant advances in smart spectrophotometer technology, many operators still use outdated instruments. Using a spectrophotometer without state-of-the-art features is a bit like being forced to make calls from a rotary phone—outdated technology slows down workflows and leads to manufacturing inefficiencies and errors. This is why you should consider making the switch to smart spectrophotometers in your lab. Smart technology improves productivity, data management, and operator learning curves, allowing you to maximize your operators’ time and, ultimately, produce higher-quality products.

Smart spectrophotometers like the Aeros improve workflow by speeding up the sample preparation process and making it easier to record measurements. Image Source: HunterLab

Appropriate color measurement tests can help you create fiber cement siding that is as beautiful as it is durable. Image Source: Shutterstock user Kiattisak Thongtawee

Fiber cement siding—a sturdy combination of wood pulp, fly ash, portland cement, and water—was first introduced in the construction industry just 25 years ago.1 Since then, it’s become one of the most popular materials that architects use for their projects. Almost 15 percent of all new homes have fiber cement siding, in part because this material is so durable and versatile. Although this material can be made to look just like brick, stone, or wood siding, it is actually far stronger than wood or vinyl materials, and less expensive to make than brick or stone. Quality fiber cement siding is fire resistant, termite-proof, rot-proof, and can withstand extreme weather conditions like heavy rain, strong winds or fluctuations in temperature.

But in order to achieve both the durability and beauty of fiber cement siding, manufacturers have to use appropriate color measurement methods at different points in the manufacturing process. Siding color is often the first thing that visitors notice when they look at a house, which is why it’s so important to test for color accuracy before you sell your products to customers. Even subtle inconsistencies in color could make fiber cement siding appear cheaply-made or weather-worn, and will negatively impact the overall appearance of the house. By using spectrophotometric color measurement during manufacturing, you can ensure that every piece of fiber cement siding meets your exacting standards and that your final product will appear beautifully-crafted.

Unpainted fiber cement siding is usually light grey in color. Image Source: Wikimedia user Michael Holley

A change in season can affect how we perceive colors due to varying cone sensitivity and activation in response to ambient colors. Image Source: Unsplash user Lukasz Szmigiel

By now, the subjective nature of color perception is well-known. Biological, cultural, and contextual factors combine to produces variation in our assessments, experiences, and descriptions of chromatic information. Research shows that even fleeting mood variations can impact our ability to distinguish between particular colors.1 However, there is one color whose perception has been considered remarkably stable across viewers and cultures: yellow. While humans can see red, yellow, green, and blue as discrete colors free from other hues, the specific wavelengths at which people identify unique red, green, and blue vary. The wavelength of unique yellow, however, remains particularly constant across populations. A recent attempt to better understand this phenomenon revealed a new and unexpected source of perceptive variation.

Yellow appears to have unique optical qualities that make perception unusually stable across populations. Image Source: Unsplash user Eric Saunders

Modern color measurement technologies go beyond the subjective human gaze and allow us to objectively quantify a rainbow of colors. Image Source: Unsplash user Denise Chan

Color surrounds us every moment of our lives and affects our emotions, behaviors, and beliefs in large and small, conscious and unconscious ways. Color can set a mood, warn us of danger, give us critical information, and even bring us joy. Despite the universal presence of color, describing it remains elusive, in part due to variations in color perception from person to person and in part due to a lack of descriptors for each of the millions of shades seen by the human eye.

Instrumental color measurement moves beyond the limits of human perception and vocabulary and allows us to capture color information as objective data, creating a common language of color that is essential for communication within and between industries around the world. The two most advanced color measurement instrument types are colorimeters and spectrophotometers, both of which use sophisticated technologies to accurately and precisely quantify and define color.

While closely related, these instruments have unique qualities that may make one more suitable than the other for a particular type of measurement.1 Understanding the characteristics of a colorimeter vs. spectrophotometer can help you select the best tool for your application.

Colorimeters are ideally suited for evaluating final color results and identifying unwanted color variations. Image Source: Pexels user Karolina Grabowska

What Is a Colorimeter?

A colorimeter is designed to perform a type of psychophysical sample analysis by mimicking human eye-brain perception, which means its measurements correlate to human perception.. In other words, it is designed to see color the way we do.

Its results are direct and read as tristimulus values. A tristimulus value is one that identifies a color with characters that represent different dimensions of its visual appearance. A tristimulus value may contain values like X, Y and Z or L, a and b. The “gold standard” for tristimulus colors is the CIE Color System, developed by the International Commission on Illumination — the CIE in the title stands for the French version of their name.

There are a few unique components involved in a colorimeter.

• Illuminant: The illuminant represents a specific light source, such as daylight or incandescent light, to project consistent brightness onto the object. In a colorimeter, an illuminant is fixed.
• Observer: The standard observer offers a specific field of view with which to analyze the colors. A colorimeter usually uses a 2-Degree Standard Observer, which is suitable for color evaluation and quality control.
• Tristimulus absorption filter: The absorption filter isolates specific wavelengths to be applied to the sample.

Color measurement solutions like spectrophotometers help you spot the difference between a dark bean and a burnt one. Image Source: MaxPixel user Nikon D7100

Although lighter roasts have a greater number of flavors than dark roasts, the reality is that many customers still prefer dark roast coffee. In fact, an estimated 42 percent of consumers drink dark roast coffee each day, compared to just 15 percent of consumers who drink light roast coffee.1 This is why many coffee manufacturers choose to make both styles of beans in an effort to cover the full spectrum of the market.

However, just because these dark roast drinkers prefer a bolder coffee doesn’t mean that they want their coffee to taste burnt. To cater to the large population of dark coffee drinkers in the United States and perfect your roasts, you need to have a system of color measurement solutions designed specifically for coffee beans. After all, just a few minutes too long on the roaster could mean the difference between a bold, dark bean and a burnt one.

Some beans are so dark in color that it’s difficult to tell whether they’ve been roasted for too long. Image Source: Wikimedia user Dan Bollinger