Fabric is thin, but also sturdy and opaque. They feel tight and structured when you put them on. Fabric is very smooth, but not the soft, flexible feeling of most leggings or some other Boody products. I sized down because I am always disappointed by baggy leggings, but I'm not sure yet if that was the right choice. (Bought small, hips are 38, waist 27). I have short legs and was delighted that they were only slightly too long, and the excess easily tucked under itself. I got the athletic leggings because after reading reviews, they seemed like they would be thicker. There is NO show through, but they have a curved seam detail at the hips (see picture) and one below the front knee. These weren't visible in the images online and since I planned to wear these as pants in regular life, I don't really like that detailing. They seem very well constructed, but do have a fair amount of thread ends that were left untrimmed, which I can easily do myself.