375 GSM is a substantial weight for a curtain fabric — noticeably heavier than most standard ready-made curtains, which typically sit between 150 and 280 GSM. In practice, this weight means the panels hang with a fullness and density that lighter fabrics can't replicate. They move slowly and deliberately when opened or closed, pool beautifully if you allow extra length, and reduce light and sound more effectively than thinner alternatives. The weight also means they hold their position in a draught rather than floating away from the window — a small thing, but one you notice immediately.