What Are Mattresses Made Of? We Reveal What's REALLY Inside

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James Miller
By 
James is an environmentalist, sustainability expert and senior editor at TheRoundup, specializing in testing non-toxic, organic and eco-friendly products. James, his wife and two daughters believe in chemical-free and zero-waste living. They aim to leave the planet in a better state than we found it, for future generations to enjoy.
James Miller
Updated: April 15, 2024

Mattresses are an item we all use and take for granted, but have you ever wondered what a mattress is made of?

Most people have no clue how mattresses are put together or how the materials used can affect their sleep, health, and the environment.

Mattress materials range from traditional innerspring and memory foam to organic latex and bamboo (often found in eco-friendly organic mattresses). Each material and the layer it's used in significantly impacts mattress performance and comfort.

I've been testing sleep products for over 12 years and have dissected hundreds of mattresses. Today, I'll lift the lid on your mattress (without cutting it open...promise! ????) and show you what's inside...

What Are the Different Mattress Layers?

diagram showing layers inside a mattress

Understanding the different layers is crucial in appreciating how they provide comfort, support, and durability.

Each layer serves a specific purpose, working together to enhance your overall sleep quality.

Comfort Layer

The comfort layer is the top layer.

It defines the initial comfort and feel of a mattress. It contours to your body, providing cushioning and pressure relief.

Common materials include foam and latex. This layer also often contains natural fibers like silk or wool to add luxury and improve temperature regulation.

Transitional Layer

The transitional layer is a buffer between the comfort and support core.

It contributes to the overall firmness and deep support of the mattress. Its primary role is to ensure you don't sink too deeply into your mattress.

Materials like responsive polyfoam or denser latex are used in this layer.

Support Core

The core is crucial for overall mattress support, shape retention, and durability.

It's typically made of high-density foam, innerspring coils, or a combination of both.

Cover

The cover is the outermost layer. It protects the inner layers and can add extra comfort, breathability, and aesthetic appeal.

Some covers are designed with zippers for easy removal and cleaning, enhancing the mattress's hygiene and longevity.

Cover materials vary from simple fabrics like polyester to advanced, eco-friendly fabrics like organically sourced cotton and TENCEL.

What Materials are Inside Your Mattress?

Innerspring Coils

spring coils inside a mattress

Innerspring mattresses are known for their traditional coil support system.

The coils are typically made of steel. They provide support and influence firmness and longevity.

There are several types of coil systems:

  • Bonnell Coils: The oldest and most common type. Often found in budget-friendly mattresses.
  • Offset Coils: Designed to conform more to your body. Helps reduce motion transfer.
  • Continuous Coils: Formed from a single piece of wire. Offers durable and stable support.
  • Pocketed Coils: Individually wrapped. Reduces motion transfer and provides targeted support.

Pros

  • Firmness Variety: Suitable for various sleep preferences
  • Breathability: The space between coils allows for airflow
  • Cost-Effective: Often more affordable than other mattress types

Cons

  • Noise Potential: Can be noisy with movement
  • Limited Motion Isolation: Not always ideal for those sharing a bed

Memory Foam

memory foam

Memory foam is a viscoelastic material known for its pressure-relieving properties and ability to contour your body.

Initially developed by NASA, memory foam adapts to body heat and weight, resulting in a personalized sleep experience.

Pros

  • Pressure Relief: Contours your body and helps distribute weight evenly
  • Motion Isolation: Absorbs movement, ideal if you share a bed
  • Spinal Support: Maintains good alignment beneficial for back health
  • Hypoallergenic: Resists dust mites and allergens
  • Longevity: Long-lasting with proper care
  • Quiet: No noise during movement.

Cons

  • Heat Retention: Tends to trap body heat
  • Feeling of Sinking: You may find the contouring too restrictive
  • Smell: Initial chemical smell due to off-gassing VOCs
  • Weight: Often heavy and difficult to move
  • Temperature Sensitivity: Firmness varies with temperature

Latex

LATEX

Latex comes from the sap of rubber trees and is highly valued for its robustness.

There are three main types:

  • Natural: Extracted from rubber trees. Offers excellent levels of eco-friendly resilience.
  • Synthetic: Man-made and costs less. It mimics some of the properties of natural latex.
  • Blended: Made from a combination of natural and synthetic latex.

There are also two main styles:

  • Dunlop: Known for its denser and firmer feel. The liquid latex is poured into a mold and then baked. This method results in a more cost-effective product.
  • Talalay: Involves a more complex manufacturing process. The mold is partially filled, and air is added to expand the latex evenly. This results in a lighter, more consistent, and softer material.

Pros

  • Durability: Excellent longevity and resilience
  • Supportive: Provides body support and responsiveness
  • Eco-Friendly: Natural latex is sustainable and biodegradable
  • Cooling Properties: Natural breathability helps prevent overheating
  • Hypoallergenic: Natural latex is resistant to dust mites and mold

Cons

  • Cost: Natural latex is generally more expensive than synthetic materials
  • Weight: Can be heavy and challenging to move
  • Potential Allergies: Not the right choice if you have a latex allergy (maybe a latex-free mattress is a better option for you?)

Polyfoam

polyurethane foam layer

Polyfoam, or polyurethane foam, is a versatile material often used in mattress layers (usually in base layers for support and top layers for comfort).

It's less dense and less expensive than memory foam, making it a popular choice in budget mattresses.

It's not as contouring as a memory foam mattress but still offers decent support and comfort levels.

Pros

  • Lightweight: Easier to handle and move compared to denser options
  • Affordability: More budget-friendly
  • Balanced Support: Offers a reasonable level of comfort and support
  • Versatility: Used in various layers for different purposes
  • Less Heat Retention: Generally retains less heat than memory foam

Cons

  • Less Durable: Prone to quicker degradation compared to higher-density foams
  • Sagging: Can lose shape and support with heavy use over time
  • Environmental Impact: Made from petrochemicals
  • Off-Gassing: May release volatile organic compounds (VOCs) initially
  • Variability in Quality: Wide range in quality and lifespan among products

Wool

organic wool balls

Wool is a natural material often used in the top layers of mattresses.

It's a popular choice for crib mattresses due to its comfort, ability to regulate temperature, and natural flame-retardant properties.

Pros

  • Thermal Regulation: Keeps you warm in winter and cool in summer
  • Natural Flame Resistance: Reduces the need for chemical flame retardants
  • Sustainable: A renewable resource
  • Comfort: Adds a plush, comfortable layer to mattresses
  • Hypoallergenic: Resistant to mold, dust mites, and mildew

Cons

  • Cost: Tends to be pricier than synthetic alternatives
  • Allergy Concerns: Not suitable if you're allergic to wool
  • Vegan Considerations: Not an option if you're living a fully vegan lifestyle (maybe a vegan mattress is a better option for you?)
  • Care Requirements: Requires more care than synthetic materials
  • Variability in Quality: The quality of wool can vary, affecting the comfort and robustness of some mattresses

Cotton

organic cotton used to make a crib mattress

Cotton is a breathable and soft material. It's commonly used in mattress covers and batting.

Organic cotton is much more sustainable than traditional cotton. It's a popular material in eco-friendly organic mattresses.

Pros

  • Breathability: Promotes good air circulation
  • Comfort: Soft and comfortable against the skin
  • Sustainability: Organically-grown cotton is an eco-friendly choice
  • Hypoallergenic: Suitable for sensitive skin (especially organic)
  • Natural: Organic cotton is free from synthetic materials and chemicals

Pros

  • Moisture Absorption: Can lead to mildew if not properly stored and maintained
  • Robustness: Traditional, non-organic cotton may be less durable
  • Pesticide Use: Non-organic cotton involves high pesticide use
  • Shrinkage: Cotton can shrink if not properly cared for
  • Cost: Organic cotton can be more expensive

Bamboo

close up of bamboo plants

Bamboo fabric is gaining popularity for its sustainability and softness.

It's often used in the covers of bamboo mattresses.

Pros

  • Sustainable Growth: Bamboo grows rapidly with minimal water use
  • Antibacterial and Hypoallergenic: Naturally resists bacteria and allergens
  • Softness: Offers a smooth, comfortable feel
  • Breathability: Promotes air circulation and temperature regulation
  • Eco-Friendly: A greener alternative to synthetic materials

Cons

  • Chemical Processing: Some bamboo fabrics are produced using harsh chemicals
  • Blended Fabrics: Often mixed with synthetics to enhance longevity
  • Transparency in Production: Not all bamboo products are created equally sustainable
  • Care and Maintenance: Bamboo fabric may require specific care instructions to maintain its beneficial qualities

Flame Retardants

Flame retardants are chemicals added to materials to meet fire safety standards.

Pros

  • Enhanced Safety: Crucial for slowing fire spread
  • Regulatory Compliance: Meets legal fire safety standards.

Cons

  • Health Risks: Concerns over potential links to health issues.
  • Environmental Impact: The chemicals used can negatively affect the environment
  • Transparency Issues: There is often a lack of clarity from manufacturers about which chemicals are used

Greener Foams

Greener foams, such as plant-based memory foam, are more eco-friendly than traditional foams.

However, caution is needed when shopping for greener foams as the industry is rife with greenwashing. For example, 1% plant-based materials do not instantly make memory non-toxic and sustainable.

Pros

  • Eco-Friendliness: Lower reliance on petroleum-based products
  • Breathability: Tend to be more breathable than traditional foams
  • Innovation: Represents advancement in sustainable materials

Cons

  • Cost: Typically more expensive than conventional foam
  • Partial Synthetic Content: May still include some non-eco-friendly materials
  • Variability in Green Claims: Some products might not be as green as advertised
  • Limited Availability: Fewer options compared to traditional foams

Polyester

Polyester is a synthetic material commonly used in mattress fabrics for its long-lasting nature and affordability.

It's created through a process that starts with refining petroleum. This is combined with chemicals and water to form a polymer resin. This resin then undergoes further processing to be transformed into polyester fibers.

Pros

  • Durable: Resistant to wrinkles and shrinking
  • Affordable: Generally more cost-effective than natural fabrics
  • Easy Maintenance: Simple to wash and care for
  • Color Retention: Holds dyes well and maintains color over time

Cons

  • Breathability: Less breathable compared to natural materials
  • Static Electricity: Can generate static, which may be uncomfortable when sleeping
  • Environmental Concerns: Made from petroleum, a non-renewable resource
  • Comfort: May not feel as soft or luxurious as natural fabrics

Gel-Infused Foam

Gel-infused foam is a blend of traditional memory foam and cooling gel particles.

This hybrid material aims to address the common heat retention issue.

Pros

  • Temperature Regulation: The gel works to dissipate body heat, providing a cooler sleeping surface
  • Pressure Relief: Like traditional memory foam, it contours to the body, offering excellent pressure relief
  • Motion Isolation: Minimizes motion transfer

Cons

  • Variable Gel Quality: The effectiveness of cooling can vary depending on the quality and amount of gel used
  • Environmental & Health Considerations: While better than some traditional foams, gel options still contain chemicals or processes that are not eco-friendly or great for your health

Silk & Cashmere

Silk and cashmere are renowned for their luxury and comfort and are often used in some of the world's most expensive mattresses.

Silk is a natural protein fiber known for its softness and sheen.

Cashmere, derived from cashmere goats, is prized for its softness and warmth.

Pros

  • Luxurious Feel: Both materials add a touch of luxury and increased comfort
  • Temperature Regulation: Silk and cashmere are excellent at regulating temperature
  • Durability: When properly cared for, both are surprisingly durable

Cons

  • Cost: Both materials are expensive to buy
  • Care: Careful maintenance is needed to preserve their quality

Horsehair

Horsehair, specifically horses' mane and tail hair, has been used in mattress-making for centuries.

Pros

  • Natural Support: Horsehair provides a unique springiness, enhancing mattress support
  • Breathability & Moisture Wicking: Excellent for regulating temperature and keeping your sleeping surface dry
  • Longevity: Horsehair mattresses last a long time

Pros

  • Cost: An expensive luxury material
  • Maintenance: Requires regular airing and proper care for longevity
  • Sourcing Issues: You should always consider how the horsehair is sourced to ensure it's fully ethical

Coconut Coir

Coconut coir is a natural fiber extracted from coconut husk.

It's a sturdy and natural material that provides a firm and supportive mattress layer.

Pros

  • Sustainability: A natural byproduct of coconut harvesting
  • Firm Support: Produces a firm and supportive sleep surface
  • Longevity: Known for its long-lasting properties
  • Breathability: The open structure of coconut coir increases air circulation and generates a cooler sleep environment

Cons

  • Firmness: Might be too firm for some sleepers
  • Weight: Mattresses with coir can be heavier and more difficult to move
  • Availability: Not as widely available as other materials

TENCEL

TENCEL is a brand name for Lyocell. It's becoming increasingly popular in the mattress industry for its eco-friendly and comfortable properties.

TENCEL is made from wood cellulose, primarily from eucalyptus trees

Pros

  • Eco-Friendly Production: The manufacturing process is more sustainable than that of many synthetic materials
  • Moisture Wicking: Excellent for managing moisture and keeping your sleep surface dry and comfortable
  • Comfort: Offers a luxurious feel

Cons

  • Cost: Can be more expensive than more traditional mattress fabrics
  • Care: Requires specific care to maintain its quality and longevity

Recycled Materials

Recycled materials, such as steel coils or recycled plastics and fabrics, can be repurposed to create new mattresses.

Pros

  • Environmental Impact: Reduces waste and conserves resources
  • Innovations in Sustainability: Showcases creative ways to reuse materials
  • Quality: Often matches the strength and comfort of new materials

Cons

  • Variability: The quality of recycled materials can vary
  • Availability: Not all mattress brands offer recycled options
  • Cost: Recycled option can sometimes cost more

How Mattress Materials Certifications Can Keep You Safe

Certifications ensure mattress materials meet specific health, environmental, and quality standards.

They assure you that an independent organization has rigorously tested and verified the materials.

Some of the best certifications to look out for when buying a mattress include the following:

How Have Mattress Materials Evolved?

Ancient mattresses, dating back thousands of years, were basic and often filled with natural materials like straw, wool, or leaves. These were then covered with animal skins or simple fabrics.

Fast forward to the Renaissance, and we see the introduction of luxurious materials like silk and velvet.

The spring mattress was invented during the Industrial Revolution, revolutionizing comfort and support.

By the mid-20th century, memory foam started gaining popularity, offering enhanced comfort and body support.

The end of the 20th century and the start of the 21st century were characterized by a surge in eco-consciousness, leading to the development of greener materials like organically grown cotton and sustainably manufactured bamboo.

Frequency Asked Questions

What materials are in a hybrid mattress?

Hybrid mattresses typically combine innerspring coils with layers of foam. For more details about the inner workings of hybrid mattresses (and also innerspring, foam, gel, waterbeds, airbeds, pillow tops, adjustable beds, and more), check out my Which Mattress Material is Best? article.

What are PBDEs?

PBDEs (Polybrominated Diphenyl Ethers) are a group of chemicals that were once commonly used as flame retardants in various products, including mattresses. Concerns about their health and environmental impacts have led to a ban in most countries.

What materials are in a flippable mattress?

Flippable mattresses often have a symmetrical construction with comfort layers on both sides and a supportive core in the middle. These layers can include foam, latex, or mini coils designed to offer balanced support and comfort from either side.

Are hard or soft mattresses healthier?

The healthiness of a mattress depends on your individual needs and preferences. A medium-firm mattress is generally recommended for back support. However, the best choice varies based on your sleeping position, body type, and personal comfort preferences.

What's the environmental impact of disposing of old mattresses?

Many mattresses can be challenging to recycle and often contribute to landfill waste. Choosing a mattress with recyclable or biodegradable materials can minimize environmental impact.

The Final Word

A mattress is made up of multiple layers (comfort, transitional, support core, and cover), each of which can be made of different materials.

From long-lasting but potentially noisy innerspring coils to eco-friendly but expensive materials like organic latex, every mattress component offers unique benefits and challenges.

By prioritizing eco-friendly options and understanding how certifications like CertiPUR-US and GOTS can improve the air you breathe when sleeping, you can make informed choices that align with your sustainability values and health goals.

Get In Touch

Do you love a natural latex mattress? Or is a metal coil spring system more to your liking? Do you know what to consider when looking for the best mattress materials for your personal sleep needs? Drop me a line and let me know.

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James Miller
James Miller
James is an environmentalist, sustainability expert and senior editor at TheRoundup, specializing in testing non-toxic, organic and eco-friendly products. James, his wife and two daughters believe in chemical-free and zero-waste living. They aim to leave the planet in a better state than we found it, for future generations to enjoy.
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