John Lewis Heavy Bump interlining material is for use between the face and lining fabric of curtains and blinds. It gives body to finer fabrics such as silks, polyesters and thin cottons and adds a particularly luxurious look to your curtains. It can also add extra protection to curtain fabrics to prevent light damage as well as blocking out sound and draughts. Made in the UK If your fabric is in stock, we'll usually deliver it within 5 working days.