A band cut on the bias (in a 45° degree angle across the corner) from rectangular linen fabric.

Learning of the day: Unless you cut the band "on the bias" your neckline band will never be nice and flat. These early medieval folks that had their dress neckline done this way surely could afford to waste a lot of fabric. Rich people... 😅 #neckline #sewing #pleating #howtheheckdoesthiswork