Fabric with diagonal ribs is a type of textile material that has a distinct pattern of diagonal lines running across its surface. The two most common types of fabric with diagonal ribs are serge and TWILL. Serge is a type of fabric with a smooth, even weave and diagonal ribs that run in the same direction. TWILL is a type of fabric with a diagonal rib pattern that runs in both directions. Both fabrics are strong and durable, making them ideal for use in clothing and upholstery.