EIGHT-YEAR-OLD Brandon Chan will return to school this week with a spring in his step and a new bag on his shoulders. Last week he received what looks like an over-sized briefcase with shoulder straps - shipped Federal Express from France. Brandon is not the only student at the French International School equipped with what is known in France as a cartable. Although they are not available in Hong Kong, this book bag is popular among students at the French school. ''He has been asking for one and he is getting to the age where he becomes a little particular,'' Brandon's father, Kennis, said. And although it may seem a small issue, for most students returning to school this week, the type, size, and colour of their bag is important. Among the smaller children, a brightly coloured bag emblazoned with their favourite idol or cartoon character is currently the trend. Dragon Ball's Son Goku is one such character, although eight-year-old Laurence Hall prefers to tout Jurassic Park on his back. One of his friends has a Ninja Turtle bag. Another has Felix the Cat. ''My friends have different bags,'' Laurence said. ''Black, yellow, red. I've always wanted to see this film so I got this one.'' Among the very young, there is no set style to which they adhere. Although 10-year-old David Ho's friends like the fiery coloured bags, he prefers the plain ones. Secondary students look to other designs. At the Island School, the trend among girls seems to be environmental Nepalese cloth bags hung from one shoulder instead of both. ''They are nothing big or fancy, just cloth bags over the shoulder - it's easier to carry over one shoulder,''16-year-old Kiran Panjabi, of Island School, said. ''The guys carry tennis bags like Nike and Prince.'' Other students, particularly those at Chinese schools, will pay high prices to stay among the chic. Some will pay between $500 and $1,000 for a Junior Gaultier bag, or between $980 and $1,250 for a Mandarina Duck bag. Ralph Lauren is also popular among the more trendy girls. But the most important thing about your school bag - no matter what label - is that it is strong enough to handle heavy loads of text books without damaging your back. Studies by the Hong Kong Society for Child Health and Development suggested the weight of school bags was one factor leading to defects in the spines of some students. Some young students, who carry at least 10 books, need to think twice before loading their bags. Many bags are so crammed students drag rather than carry their bags. The result is that before the end of the year not only are their bags worse for the wearbut also their backs. Orthopaedic experts believe bags weighing more than one-tenth of a child's body can be damaging to their health. The way in which bags are carried and the durability of the cloth are important when making a selection. Bags should be well-made and worn over both shoulders to give proper support. A spokesperson for the Education Department said it has recommended that schools supply lockers and lockable desks so students can leave textbooks overnight. But if these are not available, he recommends students pack their bags according to their timetable.