These gaffs from Undrowear are made of cotton fabric and lace on the back.
Tucking panties, also called gaffs, have a "flattening effect." They are used to pack the external genitalia and make the bulge (elevation) less visible, to give you the curves that feel best for your body.
What sets these apart from other panties? The crotch area is cut wider and the front is made of 3-layer reinforced fabric for better support. Along the edges of the crotch is elastic lining that helps for a better fit against the skin.