What does Skewing mean?
A process in the fabric creation that helps to prevent leg twist that can occur during the shrinking process. To mitigate this effect, skewing is done in the opposite direction of the twill direction by a degree.
Heddels explains Skewing
Created to prevent leg twist, skewing was patented in 1976 by Karin Hakanson. Depending on the twill direction, the fabric is skewed in the corresponding direction to remove tension from the threads. Thus, right hand twill is skewed counterclockwise and left hand twill is skewed clockwise. A fabric’s weight, twill weave, yarn size, and yarn twist all factor into the amount of skewing a material needs. For jeans, the denim is usually skewed between 4% and 10%.
Here is denim that has gone through the skewing process.