Why Mulberry Silk
Not all silk is the same. Grade, weight, source and certification all determine whether a silk pillowcase actually delivers on its promises. Here is everything you need to know.
Most silk pillowcases are not what they claim to be
Walk into any high street store or search online and you will find dozens of silk pillowcases at wildly different price points all claiming to deliver the same benefits. They are not the same. The difference between a £19 silk pillowcase and an Orlisse pillowcase is not marketing. It is the actual material.
Most cheap silk pillowcases are not silk at all. They are polyester satin, a synthetic fabric that mimics the shine of silk but shares none of its properties. Polyester satin does not reduce friction, does not regulate temperature, and does not keep skincare on your face. It looks like silk. It is not silk.
Even among genuine silk products, quality varies dramatically. Silk is graded, weighted and certified and the difference between the lowest grade and the highest is significant. Here is what every number and letter on your pillowcase actually means.
The silk grading system and why it matters
Silk is graded on a scale from 1A to 6A based on the quality, uniformity and length of the silk filaments produced by the silkworm. The higher the grade, the longer and more uniform the filaments and the smoother, more durable and more effective the resulting fabric.
| Grade | Filament Quality | Typical Use |
|---|---|---|
| 3A | Short, uneven filaments | Budget silk products, fast fashion |
| 4A | Moderate length and uniformity | Mid-range silk bedding |
| 5A | Long, mostly uniform filaments | Premium silk products |
| 6A Orlisse | Longest, most uniform filaments available | Highest quality silk bedding and apparel |
Most brands selling silk pillowcases at £25 to £50 are using 3A or 4A grade silk. At these grades the fabric feels slightly rougher, pills more quickly, and loses its smoothness after washing. Grade 6A is the highest grade commercially available. The filaments are longer, smoother and more uniform which means more consistent contact with your hair and skin, and a fabric that maintains its quality over years of use.
"6A grade silk produces filaments so uniform that the resulting fabric is measurably smoother at a microscopic level than lower grade equivalents. This directly translates to less friction against hair and skin."
Momme weight the measure most brands hide
Momme is the unit of measurement for silk weight and density, similar to thread count in cotton bedding. It measures how many pounds a standard piece of silk fabric would weigh at a set dimension. The higher the momme, the more silk strands per unit of fabric, and the denser, more durable and more luxurious the result.
Most brands selling at lower price points use 11 to 16 momme silk. It feels light, almost too light, and starts to thin out and pill after a few months of regular washing. 22 momme is the weight used by every premium silk brand in the market because it is the point where durability, smoothness and comfort are perfectly balanced.
Why brands hide their momme weight: If a brand does not tell you their momme weight, assume it is low. Legitimate premium silk brands always state it clearly because it is one of the key quality markers. If you cannot find this information ask. If they cannot answer, do not buy.
Why mulberry silk is the only silk worth buying
Not all silk comes from the same source. The most common types are mulberry silk, tussah silk and wild silk and the differences in quality are significant.
Mulberry silk is produced by Bombyx mori silkworms that feed exclusively on mulberry leaves. The controlled diet produces silk filaments that are remarkably uniform in diameter, naturally white in colour, and hypoallergenic. This uniformity is what gives mulberry silk its characteristic smoothness and sheen.
Tussah and wild silk are produced by silkworms feeding on varied diets in less controlled environments. The resulting filaments are shorter, more irregular, and produce a coarser fabric with a slightly rough texture. Tussah silk is significantly cheaper to produce and is often blended with mulberry silk or used to make up weight in products labelled simply as silk.
"100% mulberry silk means every single fibre in the fabric is from mulberry silkworms. No blending, no shortcuts, no synthetic padding. This is the only way to guarantee the smoothness and hypoallergenic properties silk is known for."
Independent certification not just a claim
OEKO-TEX is one of the world's most respected independent textile testing and certification bodies. An OEKO-TEX certification means a product has been tested for over 100 harmful substances including pesticides, heavy metals, formaldehyde and skin irritants and verified as safe for prolonged skin contact.
This matters because a pillowcase spends 8 hours in direct contact with your face, hair and skin every single night. Any chemical residue in the fabric from processing, dyeing or finishing has extended contact time with your skin barrier. The OEKO-TEX certification removes that risk entirely.
Most silk pillowcase brands make safety claims without independent verification. Orlisse is OEKO-TEX certified which means an independent laboratory has tested and confirmed it, not us.
How to spot uncertified claims: Look for the OEKO-TEX label and certification number on the product or packaging. If a brand says safe or chemical free without referencing an independent certification body, it is self-declared and not verified.
Grade 6A. 22 Momme. 100% Mulberry. This is the standard.
When you see all three on a silk pillowcase, Grade 6A, 22 momme, 100% mulberry silk, you are looking at the highest quality specification available for a silk pillowcase. Each element matters independently. Together they define a product that will genuinely reduce hair breakage, genuinely keep your skincare on your face overnight, and genuinely last for years with proper care.
Anything less is a compromise. A lower grade means rougher filaments and more friction. A lower momme means thinner fabric that wears out faster. A silk blend means inconsistent quality and reduced hypoallergenic properties. Missing certification means unverified safety claims.
Orlisse meets all four standards. Not because it sounds good in marketing. Because it is what the product needs to be to actually deliver the results we promise.
The highest grade. The right weight. Independently certified.
Grade 6A mulberry silk, 22 momme, OEKO-TEX certified. Every Orlisse pillowcase. 30-night satisfaction guarantee.
Shop the Orlisse Pillowcase