My friends use the camp half blood t shirt for rigorous training activities. May be it is their way of showing devotion. I got a new pair just for the cool design. I like the loose casual fitting because i buy one size bigger than mine. And then the summer season gives me a perfect excuse to take that long walk in my orange camp half blood t shirt. There are a range of shades you can choose from. But orange is so much soothing to the eyes. Most people would agree with my point of view.
There are many individuals who prefer the cotton collection of tees for the entire 12 months and make it a point to wear them even during formal sessions. However, I am not that much of a hardliner in this matter. Casuals are casuals and it would be better if the occasions involves some sort of informality. The rest is, of course, your choice.