What Is Mulberry Silk? A Complete Guide to the Finest Silk

Mulberry silk is widely regarded as the highest-quality silk available today. As a natural material, mulberry silk is valued for its consistency, purity, and performance in prolonged skin contact. Known for its exceptional smoothness, breathability, and skin-friendly properties, mulberry silk has long been used in premium sleepwear, mulberry silk pillowcases, silk pillowcases, and high-quality silk bedding designed for comfort and long-term use.

But what exactly is mulberry silk?

How does it differ from other types of silk or satin fabrics?

And why is it especially valued for sleep, skin, and hair?

This guide explores mulberry silk from the material level—its origin, characteristics, production, and practical benefits—so you can understand what truly sets it apart.

Mulberry silk is a natural protein fiber produced by domesticated silkworms (Bombyx mori) that feed exclusively on mulberry leaves. It is widely regarded as the highest quality silk due to its controlled production environment and fiber consistency, and authentic products are often described as pure silk or 100% pure mulberry silk.

The International Sericultural Commission (ISC) classifies mulberry silk as the only form of cultivated silk, reflecting its controlled diet and carefully managed production environment.

Because the silkworms are raised under stable conditions and consume a single, consistent food source, the silk fibers they produce are:

• Exceptionally long and continuous (approximately 1,000–1,300 meters per filament)

• Uniform in thickness and structure

• Naturally light in color with minimal impurities

These qualities result in a fabric that is smoother, stronger, and more consistent than other types of silk.

The history of mulberry silk spans more than 4,000 years.

• Around 2700 BCE: Ancient Chinese records credit Lady Leizu with introducing sericulture and silk reeling.

• Ming Dynasty: The agricultural text Tiangong Kaiwu documented the full silk-making process, from mulberry cultivation to thread extraction.

Modern high-grade mulberry silk continues to follow these foundational principles, refined through contemporary quality control standards.

High-quality mulberry silk production emphasizes environmental control, fiber integrity, and process stability. The main stages include:

Mulberry cultivation

Mulberry trees are grown to provide a consistent and renewable food source.

Silkworm rearing

Bombyx mori silkworms are raised in hygienic, temperature- and humidity-controlled environments.

Cocoon formation

Each silkworm produces a complete cocoon containing a single continuous filament.

Reeling (fiber extraction)

Controlled physical processing allows the continuous silk filament to be released and collected intact.

Twisting and weaving

Multiple filaments are combined and woven into silk fabric.

Finishing and dyeing

Certified facilities apply finishing processes designed to preserve silk’s natural performance.

Because mulberry silk fibers are long, continuous, and structurally uniform, the resulting fabric offers excellent durability and greater consistency compared to many other types of silk. This is one of the reasons mulberry silk is widely considered the highest quality silk and valued in applications where durable silk fabrics are essential.

Note:

Some stages of silk processing are energy-intensive, which is why modern producers focus on improving efficiency and adopting cleaner production standards.

Not all smooth fabrics offer the same performance. 

*Cradle-to-gate lifecycle estimate.

Compared with other silks such as tussah silk, mulberry silk offers finer fibers, lower surface friction, and greater uniformity, contributing to a smoother feel and more predictable performance in sleep-related products.

Compared to polyester satin, real silk—especially high-grade mulberry silk—offers lower surface friction, better moisture balance, and superior breathability, making it more suitable for prolonged contact with skin and hair.

Overall, mulberry silk offers a balanced combination of smoothness, breathability, and environmental performance compared to both wild silk and synthetic satin.

Mulberry silk is commonly graded from A to 6A, with 6A representing the highest quality.

According to the ISC Silk Grading Handbook (2023), 6A-grade silk is characterized by:

• Minimal fiber thickness variation

• Very low defect rates

• High durability and consistency

Premium silk sleepwear, pillowcases, and accessories typically use 6A-grade mulberry silk to ensure lasting comfort and performance. This grading system helps ensure consistent quality across high-end mulberry silk products.

Mulberry silk’s natural breathability and temperature regulating properties help maintain stable body temperature throughout the night. By reducing friction and excess heat buildup, it supports improved sleep quality and a more comfortable, uninterrupted sleep experience.

• Thermal balance – Helps regulate body temperature

• Breathability – Promotes airflow and reduces overheating

• Moisture balance – Does not excessively absorb skin moisture

By minimizing fabric pressure and surface friction, mulberry silk may also help reduce sleep creases and sleep wrinkles, contributing to a more relaxed form of beauty sleep.

Mulberry silk has a naturally smooth surface with low friction, which can help reduce irritation during prolonged contact with the skin. Its naturally low allergenic potential and resistance to dust mites make it a popular choice for people with sensitive skin.

Commonly reported benefits include:

• Fewer sleep lines and pressure marks

• Better overnight moisture retention

• Naturally low allergenic potential

The smooth surface of mulberry silk minimizes friction between hair and fabric, helping to reduce breakage, create fewer tangles, and support healthier-looking hair over time. This low-friction property makes mulberry silk especially suitable for pillowcases, scrunchies, and other hair accessories designed for overnight use.

• Reduce breakage and frizz

• Limit tangling during sleep

• Support healthier-looking hair over time

Mulberry silk is a natural and biodegradable fiber. Lifecycle assessment (LCA) studies indicate that:

• Mulberry silk has a lower carbon footprint than many synthetic fabrics

• Its durability supports longer product lifespans

• Cleaner energy and low-impact finishing can further reduce environmental impact

Mulberry silk is an animal-derived natural fiber and is therefore not classified as a vegan material. Different consumers may have different values when choosing materials.

Understanding material origins allows individuals to make informed choices aligned with their personal preferences. Those who prefer plant-based alternatives may consider fibers such as lyocell.

When selecting mulberry silk products, consider the following:

• 6A-grade mulberry silk

• Appropriate fabric weight (e.g., 19–22 momme for sleepwear and bedding)

• OEKO-TEX® certified processing

• Clear material sourcing or certification details

Proper care helps maintain silk’s appearance and performance. Hand washing or gentle machine washing with a mild detergent is recommended to protect the silk fibers and surface quality.

• Hand wash or machine wash at 30°C (86°F) using a delicate cycle and a laundry bag

• Use a pH-neutral or silk-specific detergent

• Avoid fabric softeners, bleach, and high heat

• Air dry flat and steam on low heat if needed

Mulberry silk stands apart for its natural luster, exceptional softness, and balanced performance, offering a luxurious feel without compromising durability or everyday practicality. Understanding what mulberry silk is—and how it differs from other materials—provides a solid foundation for choosing high-quality silk products with confidence.

If you are looking to experience authentic 6A-grade mulberry silk, our Classic Mulberry Silk collection is crafted with carefully selected materials and certified processes, designed to bring premium silk comfort into everyday life.