This is a very light weight, but NOT SHEAR shirt from Banana Republic. You can wear with or without an under-T top.

Also, note that BR calls tis a size XS, but it’s much larger as if it wears as a small. My sister is between a size 4-6, 5’ 7” and about 130 Lbs. She would fit into this perfectly. See measurements in photos.

Please note that this shirt tagged as an “XS” tends to be bigger than the mentioned size. My sister is a size 4 to 6 and this shirt would fit her perfectly. I included the measurements as well in the photos.