Measure from your waist down 18 inch and it's easy to see what a versatile slip length that is. It's not for your shortest minis, but 18"" half slips are ideal under knee-length or longer skirts and dresses and could become your go-to workday slip. There are many styles to choose from, too.
For close-fitting outfits, choose an 18"" microfiber slip with a bit of stretch. It will fit like a second skin and create a great smooth silhouette. For skirts and dresses with a looser drape, you can wear satin or silky embellished 18"" half slips, some with intricate lace and appliqué.