It's 100% Acrylic.
There is a bit more looseness in the fit than slim fit. It's a segment. The product on the mannequin is a size L/42/14.The Model's Measurements: Height: 189cm(6'2'') Bust: 91cm(35in) Waist: 78cm(30in) Hips: 95cm(37in); Regular Fit: Comfortable, but not wrap-around.