This is a beautiful short sleeve dress by Nancy Greer. Feels like mostly or all polyester. Wonderful plaid of purple and gray. Four buttons on the front, with a few snaps and clasps thrown in for extra security. Pleated skirt section. Built in tie at the neck with extra fabric around the collar. Fairly sheer fabric. It's in amazing shape and has years of life left. The tag says size 16, but here are the exact measurements. (be sure to reference the last photo to see how I measure dresses)

Here are the measurements laying flat:

Bust 20"
Waist 15"
Hips 28"
Length 47"
Sleeve 9 1/2"

This item is sold from a vintage boutique in Roanoke, VA.