Rag & Bone blue and black buffalo plaid blouse size medium

Excellent condition blouse from Rag & Bone. it is a gorgeous, vibrant, blue and black Buffalo check print. Since they do their tags in black, the material and fabric content is worn off. I’ve always had this blouse dry cleaned, but I don’t know the material size medium and it fits on the loose side. 20” bust 15.5” shoulders 22” length in front and it’s longer in back