Hypercolor was a line of clothing, mainly T-shirts and shorts, that changed color with heat. [1]
They were manufactured by Generra Sportswear Company of Seattle and marketed in the United States as Generra Hypercolor or Generra Hypergrafix and elsewhere as Global Hypercolor. They contained a thermochromic pigment made by Matsui Shikiso Chemical of Japan, that changed between two colors—one when cold, one when warm. The shirts were produced with several color change choices beginning in 1991. [2] [3] The effect could easily be permanently damaged, particularly when the clothing was washed in hotter than recommended water, ironed, bleached, or tumble-dried. [2]
Generra Sportswear Co. had originally been founded as a men's sportswear distributor and importer in Seattle in 1980. The company was sold to Texas-based Farah Manufacturing Co. in 1984 and bought back by its founders in 1989. In 1986, the company added childrenswear and womenswear items to their portfolio. They struggled to meet the overwhelming demand for Hypercolor products. [4] Between February and May 1991 they sold $50 million in Hypercolor garments. [5] Generra went bankrupt due to mismanagement and fading demand in 1992. [6] The Hypercolor business for the U.S. market was sold to The Seattle T-shirt Company in 1993; Generra kept the rights for the international market. [7] [8] The company emerged from bankruptcy in 1995 as a licensing business. [9] [10] The Generra name was acquired by Public Clothing Co. of New York in 2002. [11] Today, Generra Co. is a contemporary women's and men's apparel brand headquartered in New York City. [12] [13]
In the early 2000s, the technique was revived by a number of apparel brands. [2] [14] [15] In mid-2020, the color-changing clothing trend was revived yet again by several online retailers selling color-changing swim trunks. [16]
Substances that can change color due to a change in temperature are called thermochromes. There are two common types of thermochromes: liquid crystals (used in mood rings) and leuco dyes (used in Hypercolor T-shirts).
The color change of Hypercolor shirts is based on combination of two colors: the color of the dyed fabric, which remained constant, and the color of the thermochromic dye. Droplets of the thermochromic dye mixture are enclosed in transparent microcapsules, a few micrometers in diameter, bound to the fibers of the fabric.
The thermochromic droplets are actually a mixture of several chemicals—crystal violet lactone (the color-changing dye itself), benzotriazole (a weak acid), and a quaternary ammonium salt of a fatty acid (myristylammonium oleate) dissolved in 1-dodecanol as solvent. Together, these lead to a reversible chemical reaction in response to temperature change that produces a change of color.
At low temperatures, the mixture is a solid. The weak acid forms a colored complex with the leuco dye by causing the lactone ring in the center of the dye molecule to open. At high temperatures, above 24–27 °C (75–81 °F), the solvent melts and the ammonium salt dissociates, allowing it to react with the weak acid. This reaction increases the pH, which leads to closing of the lactone ring of the dye to convert it to its colorless (leuco) form.
Therefore, at the low temperature the color of the shirt is the combination of the color of the encapsulated colored dye with the color of the dyed fabric, while at higher temperatures the capsules become colorless and the color of the fabric prevails.
A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution and may require a mordant to improve the fastness of the dye on the fiber.
Denim is a sturdy cotton warp-faced textile in which the weft passes under two or more warp threads. This twill weave produces a diagonal ribbing that distinguishes it from cotton duck. Denim, as it is recognized today, was first produced in Nîmes, France.
Dye-sublimation printing is a term that covers several distinct digital computer printing techniques that involve using heat to transfer dye onto a substrate.
A T-shirt is a style of fabric shirt named after the T shape of its body and sleeves. Traditionally, it has short sleeves and a round neckline, known as a crew neck, which lacks a collar. T-shirts are generally made of stretchy, light, and inexpensive fabric and are easy to clean. The T-shirt evolved from undergarments used in the 19th century and, in the mid-20th century, transitioned from undergarments to general-use casual clothing.
Tie-dye is a term used to describe a number of resist dyeing techniques and the resulting dyed products of these processes. The process of tie-dye typically consists of folding, twisting, pleating, or crumpling fabric or a garment, before binding with string or rubber bands, followed by the application of dye or dyes. The manipulations of the fabric before the application of dye are called resists, as they partially or completely prevent ('resist') the applied dye from coloring the fabric. More sophisticated tie-dye may involve additional steps, including an initial application of dye before the resist, multiple sequential dyeing and resist steps, and the use of other types of resists and discharge.
Thermal printing is a digital printing process which produces a printed image by passing paper with a thermochromic coating, commonly known as thermal paper, over a print head consisting of tiny electrically heated elements. The coating turns black in the areas where it is heated, producing an image.
Dyeing is the application of dyes or pigments on textile materials such as fibers, yarns, and fabrics with the goal of achieving color with desired color fastness. Dyeing is normally done in a special solution containing dyes and particular chemical material. Dye molecules are fixed to the fiber by absorption, diffusion, or bonding with temperature and time being key controlling factors. The bond between the dye molecule and fiber may be strong or weak, depending on the dye used. Dyeing and printing are different applications; in printing, color is applied to a localized area with desired patterns. In dyeing, it is applied to the entire textile.
Thermochromism is the property of substances to change color due to a change in temperature. A mood ring is an excellent example of this phenomenon, but thermochromism also has more practical uses, such as baby bottles which change to a different color when cool enough to drink, or kettles which change color when water is at or near boiling point. Thermochromism is one of several types of chromism.
Ammonium bromide, NH4Br, is the ammonium salt of hydrobromic acid. The chemical crystallizes in colorless prisms, possessing a saline taste; it sublimes on heating and is easily soluble in water. On exposure to air it gradually assumes a yellow color because of the oxidation of traces of bromide (Br−) to bromine (Br2).
Thermochromic ink is a type of dye that changes color in response to a change in temperature. It was first used in the 1970s in novelty toys like mood rings, but has found some practical uses in things such as thermometers, product packaging, and pens. The ink has also found applications within the medical field for specific medical simulations in medical training. Thermochromic ink can also turn transparent when heat is applied; an example of this type of ink can be found on the corners of an examination mark sheet to prove that the sheet has not been edited or photocopied.
Vat dyes are a class of dyes that are classified as such because of the method by which they are applied. Vat dyeing is a process that refers to dyeing that takes place in a bucket or vat. The original vat dye is indigo, once obtained only from plants but now often produced synthetically.
Crystal violet lactone (CVL) is a leuco dye, a lactone derivate of crystal violet 10B. In pure state it is a slightly yellowish crystalline powder, soluble in nonpolar or slightly polar organic solvents.
A leuco dye is a dye which can switch between two chemical forms, one of which is colorless. Reversible transformations can be caused by heat, light or pH, resulting in examples of thermochromism, photochromism and halochromism, respectively. Irreversible transformations typically involve reduction or oxidation. The colorless form is sometimes referred to as the leuco form.
Zubbles is a commercial name for colored soap bubbles. Zubbles claim to fame is that they are the first colored soap bubbles that do not leave stains. Instead they fade away with exposure to air, pressure, and water.
Kermes is a red dye derived from the dried bodies of the females of a scale insect in the genus Kermes, primarily Kermes vermilio. The Kermes insects are native in the Mediterranean region and are parasites living on the sap of the host plant, the Kermes oak and the Palestine oak.
Sportswear or activewear is athletic clothing, including footwear, worn for sports activity or physical exercise. Sport-specific clothing is worn for most sports and physical exercise, for practical, comfort or safety reasons.
Thermal paper is a special fine paper that is coated with a material formulated to change color locally when exposed to heat. It is used in thermal printers, particularly in inexpensive devices such as adding machines, cash registers, and credit card terminals and small, lightweight portable printers.
Massimo Osti (1944–2005) was an Italian garment engineer and fashion designer, most famous as the founder of the apparel brands Stone Island and C.P. Company. Osti's products were a mix of his own innovations and design ideas he got from studying military clothing, work-wear, and sportswear.
Wet Processing Engineering is one of the major streams in Textile Engineering or Textile manufacturing which refers to the engineering of textile chemical processes and associated applied science. The other three streams in textile engineering are yarn engineering, fabric engineering, and apparel engineering. The processes of this stream are involved or carried out in an aqueous stage. Hence, it is called a wet process which usually covers pre-treatment, dyeing, printing, and finishing.
Fabric treatments are processes that make fabric softer, or water resistant, or enhance dye penetration after they are woven. Fabric treatments get applied when the textile itself cannot add other properties. Treatments include, scrim, foam lamination, fabric protector or stain repellent, anti microbial and flame retardant.