Mulberry Silk | Silk Pillowcases | Mulberry Silk USA

Mulberry silk is silk spun by silkworms that are fed only on mulberry leaves. The diet gives a long, even, pale thread, which is why mulberry silk is smoother and more uniform than wild silks such as tussah. Almost all silk pillowcases are mulberry silk. This guide covers the terms you will see on a product page, how to pick a size, how to look after silk and what to check before you order.

Momme: the number that tells you the weight

Silk is not sold by thread count. It is sold by momme, a unit of weight. One momme is about 4.3 grams of silk per square meter of fabric. A 19 momme pillowcase is the usual entry point. A 22 momme pillowcase uses roughly 15 percent more silk and feels a little heavier in the hand. A 25 or 30 momme pillowcase is denser again and costs more for that reason.

Heavier is not always better. A scarf or a sleep mask is often made from lighter silk on purpose, because it needs to drape or sit lightly on the face. Read the momme figure next to what the product is for.

Grade 6A and what it does and does not tell you

Many listings say grade 6A. This is a trade grading for raw silk thread, where A is the top letter and 6 the top number, and it refers to long, unbroken strands. It is a claim made by the manufacturer, not a government standard, so treat it as a description and not a certificate. Where a maker states a grade or a certification such as OEKO-TEX, we repeat it on the product page and say it comes from the maker.

Silk is a fiber, satin is a weave

This is the mistake that costs people money. Satin describes how threads are woven to give a glossy face. It says nothing about what the threads are made of, and most low-priced satin is polyester. Silk woven in a satin weave is usually called charmeuse. If a label says satin and does not say silk, it is almost always a synthetic. We only list products whose makers state they are mulberry silk.

One side or both sides

Some pillowcases use silk on the side you sleep on and cotton or another fabric on the back. They cost less, and the back grips the pillow so the case moves less. Others are silk on both sides. Neither is wrong, but you should know which one you are buying. Each product page says whether both sides are silk.

Closures: zip or envelope

Silk is slippery, so a pillow can slide out of a loose case. A hidden zip holds the pillow in and keeps the case neat. An envelope closure has a deep flap instead, with no hardware to feel through the fabric. Zips are more secure, envelopes are simpler to wash. The closure type is listed per product.

Getting the size right

A standard US pillow is 20 by 26 inches, a queen is 20 by 30 and a king is 20 by 36. Most silk pillowcases sold here follow those sizes, and the case is cut slightly larger than the pillow so it slides on. If your pillow is thick or made of memory foam, go up a size. Measure your pillow and compare it with the size on the product page.

Scrunchies, bonnets and sleep masks

A silk scrunchie is a strip of silk around an elastic core. The silk is what touches your hair, so it slides over the hair instead of gripping it the way a bare elastic does. A silk bonnet or sleep cap keeps hair wrapped in silk overnight, and a double layer cap has silk on the inside as well as the outside. A silk sleep mask has a silk face with a soft filling behind it. On each of these the page tells you what the silk part is and what the other parts are.

Looking after silk

Follow the care label first. As a general rule, wash silk in cool water by hand, or on a delicate cycle inside a mesh laundry bag. Use a mild detergent made for silk or wool. Skip bleach and fabric softener, do not tumble dry, and dry it out of direct sun. Iron on the lowest setting, on the reverse side, while the fabric is still slightly damp. Looked after this way, a silk pillowcase keeps its sheen for years.

What silk will not do

Silk is a comfortable, smooth fabric. It is not a treatment. We do not claim that a pillowcase will clear your skin, stop hair loss or fix how you sleep, and you should be wary of any seller who does. If you have a skin or scalp condition, talk to your doctor or pharmacist.

Delivery and returns

Everything we sell is held in US warehouses, so including handling most orders arrive within 3 to 7 working days of the order date, tracked. Delivery is free on orders of $150 or more and a flat $20 under that. If the silk is not right, return it within 14 days of delivery, unused, unwashed and in its packaging, for a full refund.

The short version

Check that the label says mulberry silk, not just satin. Look at the momme weight and whether both sides are silk. Measure your pillow in inches. Wash cool, dry in the shade.