There are lamps that light an interior, and there are lamps that are its jewellery. The Tiffany lamp belongs to the second category twice over: by day it’s a colourful sculpture in glass, by night – a glowing stained-glass window that turns an ordinary corner of the room into the cosiest spot in the house. Though the technique is more than a hundred and twenty years old, the dragonflies, wisteria and geometric mosaics are returning to classic and modern interiors with equal force. We explain how a real Tiffany shade is made, how it differs from an ordinary stained glass lamp, where it fits best and how to care for coloured glass so it pleases the eye for generations.