Soft lightweight fabric which I believe is Polyester but has more of a tactile feel to it like silk. I love the pattern on this blouse, it does have a couple of thread pulls and the brand tag is hanging off on one side (it could either be stitched back in or removed but I decided to leave it be), but offering up anyway as it's so cute. Button closure on the backside of the neck.

No size tag, I wear a MediumLarge and it's a wee bit tight on me, so a Small/Medium is more accurate, it seems to fit a little tighter around the stomach and billow a bit near the sleeves like a lot of eighties era tops. 

Exact measurements lying flat:

Bust is 20 inches pit to pit

length is 24 inches