Regular shirts, and other sports jerseys (but not in paintball).
Micromag RT with z-grip.
It's light weight, breathes easy, and moves well with you. The only long sleeve jersey I've ever worn during the summer in Texas that wasn't too uncomfortable. (and it was black too). Looks cool.
I wore it when it was around 105 outside, and the numbers started coming off. I called about it, and they said there's nothing they would do. I tried a few things to get the numbers to finally stick again, but wound up having to just rip them off.
It's still a good product, but the customer service has really dropped in the last year. Don't wear it outside during the summer in Texas.