Cotton twill is a weave pattern that’s characterized by diagonal lines on the face of the fabric. Cotton twill results in a sturdy fabric—in fact, denim, chino, gabardine, and drill are all types of twill fabric that you’ll recognize as popular pants’ material. Denim and chino in particular make for durable, high-quality pants and trousers. As your source text states "struttura diagonale", I thought this appropriate. There is a good closeup photo in the website.