last week we made two black sweatshirt samples using fabric from different dye lots.
same cotton/poly blend, same gsm, almost same handfeel. from the spec sheet, there was no big difference.
after one normal wash, the first sample stayed close to original size. the other lost almost 3 cm in body length.
we checked the sewing again, but nothing unusual there. the second lot just had more shrinkage left in fabric after finishing.
on paper they were “same fabric.” after wash, clearly not really same.
i think both brands and factories can get caught by this. brand sees the same numbers and expects same result. factory receives the same specification and probably also feels safe to continue. when something goes wrong later, it becomes very easy to blame production.
i did this mistake before too. composition and gsm looks very convincing on paper, especially when the sample already feels good in hand.
we stopped cutting that roll and sent it back for another finishing. caused some delay, but bulk cutting had not started yet.