10 Wallets of 7 Heritage Yarn Darner Hand Sew Needles. Each wallet contains 7 needles of the popular sizes 14 and 18 Whitecroft Heritage Premium is a range of quality products for the discerning user. Yarn Darners in sizes 14-18 are long hand-sewing needles with long wide eyes and are ideal for darning large holes while mending socks and other materials using yarn or cotton. They are also known as Wool needles and are commonly used in knitting or crocheting to sew pieces of work together.