Thats a pretty broad statement. What are you talking about? +J or regular line? Which jacket? I got a +J blazer (slim fit) and it is made of polyester and cotton blend.
sorry, it is called the "slim fit jacket" and it looks like a regular suit jacket. It also looks identical to the "slim fit blazer". It is this one..
I emailed uniqlo customer service last week and still havent heard back