Material of shirt folded to the underside. No stitches show but should be present on the underside. Cheaper shirts of this kind use the selvedge rather than stitched interlining. In the more modern plain placket, the edge of the shirt front is folded over to create a creased edge and held together by the button holes.
Hidden Button body have an extra strip behind the center for the buttonholes. Buttons are concealed behind the front center. Another but rarely seen front style is the covered placket. Here the fold is designed to cover the shirts buttons entirely. Rarely seen on off the rack shirts.
Material of the shirt folded to the outside (sometimes a seperate piece attached). Range in size from 1″ wide to 2″ wide with 1.5″ being most common. Two rows of top to hem stitching are present, commonly 1/4″ in from each edge. Stitching inset ranges from none to 1/2″. Usually made with very light interlining.