Silk Pillowcase: Envelope vs Zip Closure, Which Is Better?
Both closures work well — this comes down to preference more than right-and-wrong. Envelope closures have a tucking flap design with no hardware near your face; zip closures hold the pillow more firmly and neatly inside. The short answer: choose envelope for softness and simplicity, zip for a snug, won't-budge fit. Here's the full comparison so you can match to your own sleep style.
Envelope vs zip: which is better?
For most sleepers, envelope is the popular default — and for good reason. It's softer against the face (no hardware at all), easy to use, and suits most standard pillows well. But "better" really does depend on what you're after. If you want a soft, hardware-free surface and a pillowcase that's simple to get on and off, envelope wins. If you want the pillow held firmly and neatly with no gaping — especially on a thick or generously stuffed pillow — zip is the neater solution. Neither is objectively superior; it's about matching closure to your preference and pillow.
What is an envelope closure?
An envelope closure is an overlapping opening at the back of the pillowcase — the pillow tucks in behind a flap, held by the overlap rather than any fastener. The advantages are real: there's no zip, button or hardware of any kind to contact your face or hair, the entire sleeping surface is all-silk with no interruption, and the pillow slides in and out conveniently without fiddling with a fastener. It also gives a clean, tailored look from the front. The trade-off is a slightly looser fit — on very full or oversized pillows, the opening can gape a little at the back, though this rarely affects the sleeping experience.
What is a zip closure?
A zip closure runs along one edge or end of the pillowcase, fastening the pillow snugly inside. The strengths are a secure, tailored fit with no gaping, the pillow can't shift or creep during sleep, and the finish looks particularly neat on thicker or larger pillows. The detail to pay attention to is zip placement: a well-designed silk pillowcase positions the zip at the side or end, well away from where your face rests, so you never feel it. If you've ever woken up with a zip-mark pressed into your cheek from a cheap pillowcase, a quality silk one with good placement solves that.
Which should you choose?
Match to your sleep habits and your pillow. Envelope suits you if you want the simplest, softest, hardware-free option — particularly if you sleep face-down or on your side and want nothing at all between the silk and your skin. It also works well for standard-depth pillows. Zip suits you if you use a thick, very full or slightly oversized pillow and want a secure fit with zero gaping, or if you've found envelope cases have let your pillow shift or peek out overnight. Both are completely comfortable in quality silk; it's really a matter of which detail matters most to you.
What matters more than the closure
Worth saying plainly: the closure is a detail, and the fabric is the substance. The biggest difference in your sleep experience will come from whether the pillowcase is genuine 100% mulberry silk, at the right 22-momme weight, and OEKO-TEX certified for safe dyeing and finishing — not from whether it zips or tucks. A beautifully engineered envelope closure in thin, low-grade silk will underperform a simple zip closure in proper 22-momme mulberry silk every time. So pick your preferred closure, but make sure you're getting real silk underneath it.
Our LS Silk AU mulberry silk pillowcases are 22-momme, 100% mulberry silk and OEKO-TEX certified — available in both envelope and zip closures, in a range of colours, so you get the fit you prefer in the silk that actually makes the difference.