Vintage 80s Printed Dress Blue & Black Maximalist Party Dress Union Label

Vintage 80s Printed Party Dress Missing size tag, please see measurements Bright blue with black crescent geometric print Elastic waist Puff sleeves with button Pleated front of skirt Unlined Large shoulder pads Keyhole with button at back neckline Estimating size at around a large / XL, or 12/14. I am a 1X or 2X depending on brand and I cannot get it on, but it fits pretty loosely on this mannequin, which typically fits around a medium. It is 100% polyester, no stretch. Approximate flat measurements 22” across at the armpits (it may be intentionally oversized here?) Unstretched, the elastic waist measures about 13.5” across. Fully stretched to about 21”. Length on hanger 45” depending on how the waistline lays on you, it may sit a few inches shorter.