Corduroy is all about ribs! The lower the number of Whale, the wider and bigger the ribs. This fabric is woven with an extra thread which will be cut after weaving. By cutting the extra thread at a regular distance from eachother, the velvet ribbing comes up. Ribbing always runs in the warp direction. So the direction of the nap. must be taken into account when designing clothing. Although this fabric is usually used for casual clothing that is soft and comfortable to the touch, corduroy is sometimes additionally washed to make it even softer.;