You should keep a selection of sewing machine needles at hand so that you always have a suitable needle available: ranging from size 60 (fine) to size 100 (thick), with a normal point for all woven fabrics. The rule of thumb is as follows: the finer the fabric, the finer the point of the needle should be; with a rounded point for jersey, stretch and knitted fabrics; with a polished triangular point for thick leather; with a particularly strong point for denim/jeans. In addition, twin needles are available with normal or rounded points.