Duck is considered to be one of the durable fabrics. It is a sport weight fabric. It has a square weave, unlike twill, which has a diagonal weave. Duck is a very tightly woven fabric which makes it waterproof. It is easily washed and is resistant to snags and wind damage.
Twill & Denim, on the other hand, are heavy weight fabrics but not as durable as duck. They are hard and long-wearing yet crease easily and are resistant to wear and tear. Twill generally becomes softer with wear and fades with washing.