The velvet midi dress is described with a square neckline, three-quarter sleeves, a basque waist and a concealed side zipper. The published S–XL rows supply chest, waist and length, but those numbers alone do not show where the shaped waist seam will sit on you. Start with that position before choosing a row.

Mark the waist shape on a dress you own

Put on a dress whose waist placement feels right, then mark the point where its waistline meets your torso. A basque waist dips below the natural waist, so ask for a front photo and the vertical measurement from shoulder to the lowest point of this dress’s waist seam. Compare that point with your reference dress. The listing names the shape but supplies neither its depth nor a torso-length measurement.

Check the entry path and neckline together

The source lists a concealed side zip and stretch, without giving the zip opening length or stretch amount. Ask for a photo of the zip fully open and for finished chest and waist dimensions. The square neckline and sleeve opening are separate fit points: measure a dress you own across the neckline and upper arm if either is critical. Do not assume the decorative waist can compensate for a chest row that does not fit.

Notice what barely changes in the chart

S lists 33 in chest, 26.5 in waist and 43 in length; XL lists 37.5, 31 and 43.5 in. Chest and waist each increase 4.5 in across those rows, while length changes only 0.5 in. Compare the listed length with your preferred midi while wearing the shoes you intend to use. Ask whether the chart represents body recommendations or finished garment measurements and where its length begins. The velvet fiber content and lining are not specified.