Welt seam

A welt seam resembles a flat-felled seam but is less bulky. Rather than folding over and pressing the “top” seam allowance, it is simply finished with a serger, zigzag stitch or pinking shears and then stitched down. It provides a nice look on the inside of garments, especially on fabric like this that shreds madly. (This view is from the wrong side.)