Models presented traditional hanbok during a rehearsal of an event for the spouses of leaders attending the G-20 summit in Seoul last year. (TRUTH LEEM/REUTERS)

Fashion-watchers keeping an eye on tonight’s state dinner will be noting the first lady’s choice of designer, but the White House’s Korean and Korean-American guests have a choice: Will they opt for modern glamour or for the flowing traditional dress of Korea, the hanbok?

So, what’s a hanbok?: The traditional Korean garment is styled after those worn during Korea's Joseon Dynasty, which lasted from 1392 to the early 20th century. It’s a special-occasion dress made of silk, custom-tailored at hanbok shops where colors, embroidery patterns and accessories can be hand-picked. For women, the fundamental part of the clothing is the chima-jeogori, a full skirt (chima) that drops from under a short-cropped jacket (jeogori) to the floor. The long sleeves of the jacket curve around the elbow in a graceful arc to the wrist. For men, the basics are paji, pants that billow and are secured around the ankles with ties, and a jeogori (jacket) covered by a jokki (vest) or durumagi (overcoat). A layer of white clothing, including the women's mujigi (petticoat) and beoseon (specially seamed boot-socks), go under the colored garments. At the bottom are a pair of ggot-shin, traditional Korean shoes with pointed tips above the toes. Young unmarried women traditionally wear their hair in braids, while older, married women wrap their hair in buns at the base of their necks.

Who wore it best? Korean and American guests don hanboks for special events, ceremonies and celebrations — so some of the state dinner attendees will certainly be spotted in the traditional garb. Celebrities occasionally wear them to honor Korean hosts for sporting events and tours: Here’s golfer Michelle Wie wearing one for a photo op for the HSCB Women’s Champions golf tournament earlier this year. Paris Hilton wore a hanbok for a 2007 visit to South Korea. Venus Williams wore one for the Hansol Korea Open tennis tournament the same year. Britney Spears wore a bright pink hanbok for a Korean visit. And for the 2008 SAG awards, Korean-American actress Sandra Oh wore a hanbok-inspired couture gown.

How do you tie it? Novice hanbok-wearers could find the trickiest part of donning the traditional garment to be tying the otgoreum, the long sashes on the jacket that hang down the front of the outfit. If done well, one rounded curve of the bow will sit to one side and the two long sashes will fall to the same side, with their ends precisely the same distance apart (here’s a YouTube demonstration). A potentially embarrassing faux pas for hanbok-wearing women: If they aren’t careful to wrap one part of the skirt around from the back and hold it at their side while walking or rising, a part of the protected sok-oht (undergarments) might peep through.