Other Lessons in This Course
- How Do Mood Pencils Work?
- How a Pen Works!
- How Do Mood Pencils Work?
- How Umbrellas are Made
- How are Stress Balls Made?
- What are Magnets Made Of?
- How are Sticky Notes Made?
- How Sports Bottles are Made
- How Golf Balls are Made?
- How Injection Molding Works
- Anatomy of Pens and Pencils
- How Effective are Hand Sanitizers?
- How Ceramic Mugs Are Made
- How Are Pens Made?
- How Pencils Are Made
Color-changing items, like mood pencils and cups, alter their appearance with any change in temperature. This occurs by adding either leuco dyes or thermochromic liquid crystals (TLCs) to the product.
Do you remember your high school chemistry class? Chances are if you didn’t fall asleep, you know a little something about molecules and compounds. This basic knowledge is all you need to understand how mood items like rings, pencils, and cups change colors.
How do color-changing promos work? Why do people love these novelty items? It’s time to paint a picture and learn the amazing science behind mood products.
How Do Mood Items Work?
There has to be an extreme change in temperature in order for color-changing items to work. While you shouldn’t throw your mood pencil into a fire or blizzard, you’ll likely see a difference in appearance depending on both temperature and pressure. For example, if you squeeze a mood pencil, it will be a much different color than if you let it sit on your desk.
Of course, temperature isn’t enough to change the color of the product. There are two options for how mood items work.
The most common method is through leuco dyes. Most promotional products, like mood pencils and stadium cups, use this type of ink to change colors. Each microcapsule inside the dye contains three substances:
1. A colorant
2. An acid
3. A solvent
The solvent remains solid at low temperatures, keeping the colorant and acid close together. As a result, the mixture reflects light and creates color. When the temperature increases, the solvent liquefies and the colorant and acid come apart. At this point the dye becomes translucent, allowing any color, pattern, or word printed on an underlying layer of ink to show through.
What Are Leuco Dyes Used For?
Leuco dyes are found in a wide variety of products. They add a fun element to packaging and typical objects like pens and drinkware. Take a look at some of the surprising places you’ll find leuco dyes.
Thermochromic Liquid Crystals (TLCs)
While they’re not as common as leuco dyes, TLCs are also very effective at changing a product’s color. The crystals are fluid, but their molecules are structured and organized in a way typical of solid materials. This substance is composed of mini capsules that are covered by a chemical base. In warm temperatures (about 80ºF), the capsules reorganize like matches in a box. However, in colder temperatures, the crystals move farther apart. The final color depends on how close the crystals are together and how much white light is reflected.
Thermochromic liquid crystals work very similar to iridescent products. They are also very temperature sensitive, which means they provide a more accurate reading than leuco dyes. As such, they’re used for many important items like thermometers and other medical equipment.
What Are Thermochromic Liquid Crystals (TLCs) Used For?
Thermochromic liquid crystals (TLCs) are used for a number of essential items. From household appliances to modern technology, check out all of the uses for this substance.
The Bottom Line
Color has a huge influence on every aspect of human life. The taste of the food you eat, your productivity at work, and even the effectiveness of your medication are all impacted by color. With all that said, leuco dyes and thermochromic liquid crystals (TLCs) are welcome additions to the products we know and love. Whether you’re looking for classic mood rings or color-changing floor tiles, these substances are sure to brighten your day!
Alyssa is a super cool Copywriter at Quality Logo Products. She’s a fan of diving into the history of some of the earliest promos on the planet. If you need her, you’ll find her buried in research, in the middle of a phone interview, or singing way off-tune in her office.