A new pair of raw denim feels stiff. What factory step mostly causes that?
Show answer & explanation
Answer: Starch protects yarn
Starch protects yarn ✓ — Right. After dyeing, denim yarn is commonly sized: coated with starch to reduce abrasion and breakage during weaving. That protective coating, plus a tight weave, helps raw denim feel boardy when new. The stiffness is not a mysterious luxury signal; it is partly a manufacturing aid left in the cloth.
Indigo hardens cotton — Not quite. Indigo changes color chemistry, but it is not the main reason raw denim feels rigid. The dye can sit near the yarn surface and later abrade, yet stiffness is more tied to starch sizing and fabric construction. This is why one-washed or rinsed jeans can feel softer while still being indigo denim.
Tight weave alone — Not quite. A dense weave can help raw denim feel firm, but it is not the whole story. The distinctive boardy feel is strongly tied to sizing left on the yarn before the first real wash. That is why rinsed or one-washed denim can soften even though the weave is still dense.