The blouse is elegant and at the same time super comfortable and airy. It is made of 100% viscose - as it is on Amazon (as of today) in the product description. But the shirt is a patch with 100% polyester. Well, now what? My guess: The bottom is 100% viscose, because usually I respond to polyester. The transparent upper part, however is likely to be 100% polyester. Confirmation by fire assay: The fibers of the lower part burn as cellulose fibers, so it should be really viscose. The fibers of the top piece of fabric burn partially as polyester, partially as well as viscose, the resulting odor suggesting viscose. I can not be conclusively assessed, therefore. Theoretically, the blouse is totally transparent, so is the "Vest" equal topsy sewn. So one has the airy appearance and lets shine through anything anyway. This shirt looks like on the product photo, below it is tight, the "Vest" is firmly stitched the bottom and top, so that nothing slips. Front includes the blouse with a little button (s. Picture), an additional button is. The summer is coming, but: For false material information, there are 2 star deduction - it did not work.