In the quiet luxury world, the most powerful upgrades are the ones no one sees coming. A mulberry silk pillowcase belongs to that category. It works while you sleep, smoothing skin, taming frizz, and leaving you with the kind of rested, polished look that feels expensive before you even reach for makeup or a flat iron. Ordinary cotton or polyester pillowcases create friction that pulls moisture from your face and roughs up hair cuticles overnight. Over time, that shows up as fine lines, dullness, dryness, and morning bedhead that takes effort to fix. Mulberry silk changes the equation. Its long, uniform fibers create an ultra-smooth surface that glides instead of…