Besides its philosophy to make durable clothes for everyone, the Japanese Uniqlo brand also tries to remedy the weak points of ready-to-wear clothes through its research and development for better material. Its Ultra Light Down jacket has changed the commonly held belief that a down jacket must be heavy and bulky to be warm. The jacket uses extra fine nylon material treated with wax for smoother finish. It stuffed 90% down and 10% feather inside a single layer of material, which results in lightness, warmth, and softness. Heat Tech helps increase the softness and smoothness as if it were your second skin and help give more warmth because it improves the air-trapping quality of the material that is odor-resistant, anti-bacterial, and flexible, yet can maintain its shape.