formal dresses plus size long La Femme Off the Shoulder Ruched Gown in Black at Nordstrom, 18W Appliqué Bodice Beaded Black Lace Long Sleeve

Matsumoto explains

With its leather exterior, soft square-shaped toe, and high vamp, the design is chic, understated, and minimalist

And given the sheer number of dress options on the site (over 250 different styles at the time of publication), I also appreciate that they have pre-sorted sections like occasion dresses and night out to help you narrow it down based on what you are looking for

Velvet Phantom: Velvet Blazer & Slim Trousers A luxurious black velvet blazer, rich and plush, adds an element of sophistication and boldness

It may help to imagine a spectrum of formality, with casual wear on one end and black-tie attire on the other