Innovation That Matters

Color-changing sweater reacts to external temperature


A clothing manufacturer has introduced a sweater that changes color as the temperature rises and falls.

In 1991 Hypercolor became popular with t-shirts made using thermochromic pigments, which change from colored to colorless at certain temperatures. As the wearer’s body temperature went up or down, the t-shirt changed color. Sadly, the company making the shirts could not keep up with demand and declared bankruptcy after only a year in business. Other garment manufacturers, such as American Apparel have since experimented with special effect clothing using thermochromic dyes, but they have never caught on with the same intensity as the hypercolor t-shirts. Now, Italian men’s clothing maker Stone Island has developed an updated and fashionable version of color-changing clothing with its Ice Knit line of sweaters.

Stone Island’s sweaters are woven in two layers, with the outer layer containing thermochromic yarn and the inner later made from 100 percent wool. The thermochromic yarns are made by blending color-changing pigments with normal textile pigments. As the external temperature warms, the thermochromic pigments in the yarn become increasingly transparent, while the normal pigments retain their original color. The result is a sweater that changes color as the temperature changes. For example, if yellow normal pigment is mixed with red thermochromic ink, the result is a dye that is constantly shifting from yellow to orange as the temperature changes, creating a unique three dimensional effect.

Clothing that incorporates technology in various ways has proven popular, from a “coded-dress” which turns personal data into patterns, to winter shirts that incorporate heating pads. Although Stone Island is creating only a limited number of the thermochromic garments, will their stylish colors and sophisticated design lead to a resurgence in the market for special effect clothing?




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