Have you ever wondered about how some t-shirt colors change with heat. Well, it is a result of Thermochromic Dyeing.

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.  Thermochromic Dyeing has a similar effect.

According to Wikipedia (September 2012), “Thermochromic inks or dyes are temperature sensitive compounds, developed in the 1970s, that temporarily change color with exposure to heat. They come in two forms, liquid crystals and leuco dyes. Leuco dyes are easier to work with and allow for a greater range of applications. These applications include: flat thermometers, battery testers, clothing, and the indicator on bottles of maple syrup that change color when the syrup is warm. The most well-known line of clothing utilizing thermochromics was Hypercolor. The thermometers are often used on the exterior of aquariums, or to obtain a body temperature via the forehead. Coors light uses thermochromic ink on its cans now, changing from white to blue to indicate the can is cold.”

If you are a fashion designer and need a company to assist you with this process, you may want to contact Global Technacolour.  Global Technacolour is a specialists in Thermochromic Dyeing (heat activated color changing) and are selling their t-shirts worldwide. They have also over the years done fabrics for fashion designers Marios Schwab and Brooklyn Royalty with their fabrics at the NY Fashion Week on the Brooklyn Bridge.

By the way, Thermochromic dyes are only to do with heat, not sun. Sun activated prints are Photochromic.