It's a very light mesh, but not see-through. I think it's going to be great for hot weather workouts. We'll see how it holds up to being washed again and again, but so far this seems like a great buy compared to workout shirts at REI/Athleta etc that are $40-$60.I wear a 26 in tops so it can be hard to find decent workout shirts. This one fits well and has held up to several months of sweat and hot washes.It's a nice yoga t-shirt. It was delivered earlier than expected, which is great. I like it and recommend it.This shirt is MESH. Not what I thought I was getting, it fits but no WAY would I wear it to the gym!!This is a nice one - it's that nice stretchy lightweight athletic material. Looks nice - fits great!Very thin cheap feeling material. Not true to size.Completely see through mesh!And runs small!This quickly became one of my favorite shirts. I do not understand why so many poor reviews? It is listed as a butterfly mesh, so yes, it is see through. It is so super stretchy. I play tennis. I play tennis A LOT, in Florida heat, year round. This shirt allows for range of motion in the shoulders, provides some coverage from getting sunburned from the usual tank top, and keeps me so much cooler than any other short sleeve shirt I own. Yes, the material is not the highest quality, it has snagged over the course of months I have owned it, but I wear it often, and what do you expect for $15. This isn't a top dollar designer shirt. As far as sizing, I would not consider it a fitted or even semi fitted cut. It is more of a relaxed or loose cut and the fabric has lots of give. But if you take that into consideration while using the sizing chart, you can't got wrong. So yes, if you are looking for a fitted, full coverage top, this is NOT for you. If you are looking for a lightweight, sheer, breathable, loose fit, non designer, low cost, short sleeve budget shirt to get you through a year of intense heat, this shirt is for you.