Vintage 1960's
Pattern is cut. All pieces included. Sleeve is very worn.
Semi-fitted tunic with contrast or self bias shaped collar and bias front band with button and buttonhole trim. Concealed front zipper. Back yoke extends to front. Short sleeves with turn-up cuffs or full length sleeves gathered to bias buttoned cuffs. Side slit opening with top-stitch trim. Optional self tie or purchased belt. Semi-fitted slim skirt in above knee length and slightly flared pants with cuffs or shorts are darted to waistband.
From Wikipedia:
The bias grain of a piece of woven fabric, usually referred to simply as "the bias", is any grain that falls between the straight and cross grains. When the grain is at 45 degrees to its warp and weft threads it is referred to as "true bias."
Woven fabric is more elastic as well as more fluid in the bias direction, compared to the straight and cross grains. This property facilitates garments and garment details that require extra elasticity, drapability or flexibility.