Most institutions have formal dress codes, some do not, but if you are being gowned for a ceremony, there are definitely some things to bear in mind when choosing what to wear on the day.
The first is that traditionally most graduands wear dark clothes with light or white shirts or blouses. Ideally men wear jackets and ties and women wear skirts not trousers. Jackets are a great idea if the day is not too hot as it gives the gown a better shape and will mena your photographs will look even better. Jeans and t-shirts are definitely frowned upon. After all if you have invested time, energy and money in gaining your award, why not spend a few minutes preparing to look your best when you receive public recognition for your achievement?
Then there is the graduation hood. This is normally worn with the gown and has a loop on the back of the neck band. This is best held in place by a button on a shirt or blouse. It can be pinned but this can leave a mark or a tear on the shirt or top, so avoiding the use of pins is good.
For men, the neckband of the hood can be worn under or over your tie. Some people say there is a protocol for this, but it isn't a rule we have so far seen written down anywhere.
For ladies, wearing a low cut dress or top makes pinning the hood rather difficult, so please be aware that this is not a good idea from a robing point of view.
Weather is also a factor to bear in mind. The robes you will be wearing were originally designed as outer garments like coats or jackets and can get very warm in ceremonies. On warm days, wear lightweight clothes as changing once you are robed may not be convenient. You may have to return to the Robing Room to get your hood, gown and hat adjusted before the ceremony to ensure you look your best.
Finally, hair. The wearing of hats is traditional in many institutions and these hats come in a number of styles, the most common also being known as "mortar boards" (amongst other names). These hats do not accommodate lumps and bumps like buns, hair ties, pony tails, spiky gelled hair etc very easily. Hairgrips are normally available in the Robing Room to help keep the hat stable on your head, although our elasticated sided hats need this less often than more traditional hard sided hats.
Please bear in mind that your carefully prepared hairstyle may be squashed or otherwise spoiled by the hat, so to avoid disappointment and time spent repairing that "look" after you return your robes, try to keep your hairstyle relatively simple for this day.
We hope you have found this information useful. Ultimately the ceremony is a fun day for all, and with the right clothes under your robes, you will relax and enjoy the day to the full.

