Klasse' Universal Needles Size 100/16 5 German-Engineered Steel Machine Needles The slight ball point of the Universal Needle makes it extremely versatile. It works well on most machines and is commonly used for woven and natural fibers. Best for: Most woven fabrics and natural fibers. The finer sizes are best for lightweight fabrics. The larger sizes can be used on medium to heavy weight fabrics. Use with polyester, 100% cotton, or polyester/cotton blends. For embroidery threads, use an embroidery needle.