There are many kinds of jeans. Models include slimfit, loosefit, bootcut,... they are available for women, men, children and adults. But all of these are united by the fact that the width of the heer is narrower than the length of the heer itself. In addition, the width of the hemp is often larger at the top of the thigh than, for example, in the legs. Another unifying factor is how the cotton threads on the hew go, that the fabric works technically correctly in jeans.
"The denim fabric has the technically correct and wrong directions that need to be identified in order to make jeans."
STRECH IN JEANS
Think about whether your jeans are more flexible in length or width. If you take your jeans by the hem, will your hem be more flexible in which direction? -That's right, in width. The width of the old jeans is the correct direction of use of the denim fabric. Think about how your jeans would work if they didn't be flexible in width at all, but longitudinally yes. yes, I'd get a funny vibe, somehow weird and thstained.
And, while denim is also made without plastic, which creates this strech feature, there are differences in the flexibility of the direction of even stiffer denim fabric and the directions of the yarns that have been taken into account when sewing jeans.