Lam Wing Sum design philosophy centres around nature, colour, and playfulness while paying tribute to classic styles. In 2018, she launches her own label SUM. Starting from slow-design jewellery and now extend to garments. Celebrating the uniqueness of each individual. SUM in Chinese is "琛", from the designer's name. which means a valuable and precious treasure that represents totality. This inspired her brand aspiration, "Everything you've experienced is what makes you special." She adopts sustainable approaches not only in materials but also in design and workmanship, to explore the possibilities of the future in sustainable fashion.