OK I’ve talked to other guys and they have made the same observation. I’ve noticed it most with polo type golf shirts but also with long sleeve oxford type shirts.
Why does one collar curl up and the other curls under?
Now I’m sure someone’s going to state the obvious “cuz you’re a lazy slob who doesn’t iron their shirts” Well, there is no way I’m ironing a knit golf shirt. I don’t care that much. But if it was just an ironing thing - why wouldn’t BOTH collars curl up? Why the up AND down? I am perplexed.
maybe its the tightness and the loosness of the weave of the thread. and well one is tighter on one side than the other. Or maybe… there is something deeper behind it and by the way the curl they are trying to worn you of a future event in your life or something like that… hmmm never call tell with polo!
It has to do with the layers of fabric slipping past each other as they’re being sewn together. The parts may only nudge out of alignment by a thread’s width with each stitch, but add it up, and you can easily be off by 1/2" at the end. The excess has to go somewhere - the collar curls.
Shirts that are custom-made or otherwise carefully made will be done with the collar pieces held in alignment with pins or tack stitches to prevent this.
In mass-produced shirts, the collars go from loose parts to sewn in about 3 seconds - when someone in Guatemala is paid by the piece, they don’t wast time on nice details like making sure things are perfectly set up.
I suspect it’s because the fabric is knit as a big tube, and has a handedness (like a screw). Each row of knots is added in the same direction. This makes T-shirts sometimes twist (ie the hem will migrate in one direction preferentially around the waist).
Woven fabrics would not do this, as each row of intersections is woven in the alternate direction relative to the previous.