The shirt off your back

Shirts are important. Pants - are not.
This was my lesson (again) yesterday. Again, because I still haven't learned that people don't change. Especially people with Asperger's. If there are reasons that some shirts aren't okay to wear to school, those reasons cannot be overlooked or dismissed simply because all the acceptable shirts are in the laundry. Unacceptable is bigger than dirty. Literally, emotionally and in every other way that can define a t-shirt.
'Wrong' is 'wrong' no matter what it's made of. The details regarding why aren't really important unless you enjoy flogging yourself with irrelevant information just so there will be something else to think about. It could be anything.
Color is big - stick with primaries. Not white - those are underwear. And of course, shirts have to feel right.
No synthetics so most professional team-branded items are out.
Shirts can't have tags inside the collar.
They can never have stitching that penetrates the inside layer of fabric so that the threads annoy you all day long (for t-shirts, this is particularly tough).
T-shirts should never have stiff decals that change the way fabric breathes, moves or feels from any perspective.
These are only the specifications that I'm aware of. I'm sure there are more. Because my son has a drawer full that fits within these parameters but for reasons I can't understand, "They're not right."
Imagine how hard it is to find something as complicated as a friend when you can't even find a decent, simple t-shirt to wear!