HEATTECH was conceived and launched in 2003 to provide warmth without the thick and bulky look of traditional thermals and not at the expense of fit. The challenge is producing a material that’s light, thin and warm. At Uniqlo HQ we were shown a matrix detailing the metrics Uniqlo measures HEATTECH’s performance against. These are:
Heat Absorption: When not being worn HEATTECH is dry, the retention of moisture retains heat and its micro-acrylic structure doesn't let go of that heat, rayon and the specially developed star shape polyester yarn absorbs moisture thus also retaining heat.
Heat Retention: Air pockets within the fabric retain the body's warmth.
Stretchable comfort: Thanks to the Lycra mix HEATTECH has three times more stretch than cotton, stretching to give you a perfect fit and maximize comfort. Being able to move freely is important if you’re not going to feel constricted by your clothing.
Non-Deforming: The polyester helps HEATTECH keep its shape. The clothes are designed to be washed frequently and still look like new.
Anti-Static: Thanks to unsurpassed moisture retention properties the discomfort of a static electrical charge, especially when putting on and taking off the garment is avoided.
Odor-Control: Minimizes odors due to perspiration. Fabric wicks away and quickly dries moisture. Perspiration dries up instantly, so the fabric remains dry and refreshing.
Anti-Odor: According to Kuuni zero body odor is an especially important Japanese goal. Special fabric processing absorbs and neutralizes odors, antimicrobial qualities are designed to eliminate the four worst sources of body odor.
Soft Texture: Camellia oil is added for extra softness.
Moisture Wicking: Absorbs and releases excess moisture.
Texture: Ultra thin fabric makes for texture that is smooth and seems to glide along your skin. That's a lot.