Korean people made warm clothes using the technique of filling cotton between two layers of material which can be silk or cotton fabric and sew them together. And They used sambe(hemp) or mosi(ramie) as material to make summer clothes. Korean traditional clothes are called hanbok.

In the past, Korean people often preferred simple white clothing. That is why they are known as peaceful people and called “white-clad people” among their neighbors.

Korea also had a long tradition of enjoying colorful clothes with complex designs depending on the events and period. Today, Korea is home to many talented fashion designers who have an international reputation. 
But still, traditional clothing which is called hanbok still in used for many occasions like weddings, and other special events. With the Korean films and Tv dramas getting famous in the world, the number of foreigners who want to wear hanbok has risen. There are places you can rent hanbok for few hours. One of that place like that is called Hanboknam.
There are traditional and modern hanboks you can rent there. And you can take a Seoul tour in your hanbok or you can take a photo with it. 

  Hanbok Museum

The Hanbok Museum is located across the street from Gyeongbokgung Palace. The museum only opens on the first and the third Saturday of every month.

At the Hankbok Museum, you can learn what proper clothing they have to wear to suit the rituals Koreans go through from birth to death. All hanbok displayed at the museum are created by the hanbok designer Lee Ri-Ja. There are roughly 300 varieties on display, and some are practical enough to be worn for a daily living now. 

Kaynak: Imagine Your Korea, Hanboknam, The Book "Facts about Korea; South Korea Past and Present