Mattress

A mattress is a piece of bedding on which to sleep or lie.

In the United States it is typically constructed of multiple layers of foams, natural and/or synthetic fibers, and springs. A mattress can be used alone, on the floor, but is usually placed atop some platform so as to be higher off the ground. Such a platform might be a made with metal springs in a wooden frame. Mattresses made mainly of foam materials such as latex foam, viscoelastic foam and other polyurethane-type foam, are becoming more common. Mattresses can be constructed to use almost any support system such as air, water, foam, or springs.

If a mattress is permanently covered in fabric, this fabric is normally called the ticking.

A pillowtop queen-size mattress

Contents

History

Ancient times: Prehistoric humans simply huddled in groups for warmth at night and slept on the ground.
10,000 to 8,000 years ago (Neolithic period): The invention of the mattress and then the bed. It was raised off the ground to avoid drafts, dirt, and pests. Most probably, the first "mattress" was a pile of leaves or grass with animal skins over it. Straw was probably also used. Softer materials were added: grass, straw, pea shucks, rags, etc.
3600 BCE: The first water-filled beds were goatskins filled with water, used in Persia.
3400 BCE: Egyptian people slept on palm bows heaped in the corner of their home.
200 BCE: Mattresses in the Roman Empire were bags of cloth stuffed with reeds, hay or wool. Wealthy people filled the bags with feathers. Romans discovered the waterbed. The sleeper would recline in a cradle of warm water until drowsy, then be lifted onto an adjacent cradle with a mattress, where they would be rocked to sleep.
15th century: In the Renaissance, mattresses were made of pea shucks or straw, sometimes feathers, stuffed into coarse ticks, then covered with velvets, brocades, or silks.
16th and 17th centuries: Mattresses were generally stuffed with straw or down, placed atop a latticework of rope from which the expression "sleep tight" is derived. The latticework needed regular tightening. A typical bed of 1600 was a timber frame with rope or leather supports.

Photo on a 1940 USDA circular promoting home production of cotton mattresses

18th century: Mattresses were stuffed with cotton or wool.
Mid 18th century: Mattress covers started to be made of quality linen or cotton. The mattress cane box was shaped or bordered and the fillings available were natural and plenty, including coconut fibre, cotton, wool and horsehair. The mattresses also became tufted or buttoned to hold the fillings and cover together and the edges were stitched.
1857: The steel coil spring was invented and first patented for use in a chair seat.
1865: The first coil spring construction for bedding was patented. Mattresses were lumpy up to the late 1800s, when the box spring was invented. Even the box spring mattresses were lumpy, but at least the springs made it more comfortable.
1871: The German Heinrich Westphal is credited for inventing the innerspring mattress. He lived in Germany and died in poverty, having never profited from his invention.
1873: Sir James Paget at St. Bartholomew's Hospital presented a waterbed designed by Neil Arnott as a treatment and prevention of pressure ulcers (bed sores). Waterbeds allowed mattress pressure to be evenly distributed over the body.
1895: A few waterbeds were sold via mail order by the British store Harrod’s. They looked like large hot water bottles.
1900: James Marshall invents the pocket coil mattress
1906: Sealy Mattress Company formed after buying all patents and knowledge from a local gentlemen.
1930s: Innerspring mattresses and upholstered foundations slowly became the most widely used form of mattresses. Artificial fillers became common. The most expensive beds of 1929 were latex rubber mattresses produced by Dunlopillow. Pocket spring mattresses were also introduced. These were individual springs sewn into linked fabric bags.
1940s: Futons were introduced to North America.
1950s: Foam rubber mattresses and pillows appeared on the market.
1960s: Modern waterbed was introduced. Due to lack of suitable materials, the waterbed did not gain widespread use until this decade, when vinyl was invented. Also, adjustable beds become popular with consumers.
1980s: Airbeds were introduced. The mattress was an inflatable unit made with vinyl.
1992: Tempur-Pedic introduced their pressure-relieving "Swedish Sleep Systems" mattresses using TEMPUR branded viscoelastic memory foam.
1999: For the first time ever, the queen-size mattress beat the twin-size to become the U.S. most popular choice for mattress size.
Currently: Most mattresses use innerspring coils.

Mattress dimensions

Most mattresses have a thickness from 6 to 18 inches.

International Mattress Sizes
(Dimensions in inches. 1 inch = 25.4 mm)

Denomination USA & Canada Europe (UK) Asia (Thailand)
Twin/Single 39 × 75 36 × 75 42 × 78 × 22
Twin/Single XL 39 × 80
Double/Full 54 × 75 54 × 75 48 × 78 × 22
Double/Full XL 54 × 80
Queen 60 × 80
Olympic Queen 66 x 80
California Queen 60 x 84
King 76 × 80 60 × 78 72 × 78 × 22
California King 72 x 84
Super King 72 × 78

When does a mattress need replacing?

After 7–15 years, depending on use and quality, although many people use their mattresses longer.
Experts indicate that two adults sleeping nightly on a queen mattress will notice the padding, not the coils, breaking down after a period of four to six years. While the mattress will still be comfortable, it will no longer feel the way it did when first purchased.
When laying a hand on the mattress with about three pounds-force and sliding it over the mattress lumps can be felt.
When the user regularly wakes up feeling tired, stiff, achy and sore and the reason can be traced to the mattress.
When inner coils start springing out of the mattress.
When the mattress shows very visible deformities.
When the mattress has a large permanent sag in it.
When the box spring creaks and squeaks.
When the user has difficulty finding a comfortable position in which to sleep.

Components of an innerspring mattress

A common innerspring mattress consists of three components:

Upholstery layers, which encase the mattress core.
The spring core, also called innerspring unit.
The foundation, which many people call box spring.

Spring mattress core

The core of the mattress is the most important part in the support of the body. In most modern mattresses (except for the foam-only ones), it is made up of steel coils springs, also known simply as coils. The spring mattress core is also called innerspring. It provides support to the set. Proper support is where the wire coils push back in response to weight deflection to hold the body in alignment. The steel coil spring was invented during the industrial revolution and was first patented for use in a chair seat in 1857. Then, in 1871, Heinrich Westphal invented the innerspring mattress. He lived in Germany and died in poverty, having never profited from his invention.

Number of coils

In the past, conventional wisdom said that the more coils a mattress has, the more support it will give the user. This is not necessarily true today. The coil construction will determine the amount of support the user gets. Generally, but depending on the mattress size, they come with 300 to 800 coils. Depending on the size, 500 to 800 coils is considered firm. However, some expensive and comfortable mattress only have around 400 coils, and it takes as few as 312 coils in a full mattress to provide decent support. This is due to the use of a heavier gauge wire, resulting in more steel. Assuming that the overall coil count is decent, a heavy duty innerspring mattress may also increase the longevity of the mattress for large users.

Additionally, there are some other misconceptions as far as coil count and firmness are concerned. Doctors once said that a firmer mattress will give better support. This was actually only true with a small percentage of people, back and stomach sleepers. Most people sleep on their side, and as the side of the human body is not flat like the back, better body conformity provides better support because it put the spine into proper alignment or it's natural resting position. Usually this is achieved with an individually wrapped coil system (see below.)

Most would think that obviously heavy gauge (thick) coils will offer a great deal of support while light gauge coils will give less support. This couldn't be further from the truth. Some mattress manufacturers will compensate for a higher (thinner) gauge of steel by using a higher coil count. A low coil count and heavy gauge wire can pass as a firm mattress in the store, but it is likely that this mattress will become lumpy quickly because it does not have enough coils. Many premium mattresses feature 14-gauge (1.63 mm) coils. Coils are measured in quarter increments. The lower the number, the thicker the spring. With coils of 14 to 15.5 gauge (1.63 to 1.37 mm), it is important that the total coil count be high to compensate for the fact that they give so easily under pressure. A 12.5 gauge (1.94 mm) innerspring, the thickest typically available, may feel rock hard in a double mattress even with a coil count of 400 or less.

Connections between the coils

Generally, the number and quality of these interconnecting wires is not published by the manufacturers. If there are too few of these interconnecting wires a mattress can lose its shape more quickly than one that has an adequate amount. Mattresses that sag quickly usually have few interconnecting wires. There are some manufacturers that make individually pocketed coils, which avoid movement on different sides of the bed because they are not interconnected. However, the special pockets provide the support required by the coil instead of the interconnection with other coils.

Types of coils

Construction-wise, most manufacturers claim to have the best coil-to-gauge ratio. However, there are only a few innerspring manufacturers and four general types. One thing to remember is that while there are many different types of coils and many manufacturers, most manufacturers have their coils made by one company, Leggett & Platt.

Bonnel coils

These are the oldest and most commonly used. They were adapted from buggy seat springs of the 19th century. They are still prevalent in low priced mattresses. They have an hour-glass shape, and the ends of the wire are knotted or wrapped around the top and bottom circular portion of the coil (round-topped and self tied).

Marshal coils

Also called "pocketed coils." Each coil is wrapped in a fabric encasement, and is usually tempered twice, once with heat and once with electricity. The brand Simmons uses pocketed coils in their mattresses. Simmons also does some things that other brands that use pocketed coils don't. They "pre-compress" their pocketed coil, which means that they pack the coil into a "pocket" that is shorter (usually by a couple inches) than the coil. By "pre-compressing" the coil, it becomes firmer (sort of) because the coil is already in action (it is always pushing up.) Additionally, when two people sleep on the same mattress, the individually wrapped (or individually pocketed) coil provides motion separation (when one person tosses and turns, the other doesn't feel it.) This is important because when one person tosses and turns, it may not completely wake the other person, but, it can take them out of a deep sleep which is when the body does all of its regeneration.

Offset coils

Bonnell coils evolved into Offset coils, which are currently popular, but happen to be the most expensive ones. They are almost identical to the Bonnell coils, except that the top and bottom circular part of the coils have flat or straight sides, which allow for better hinging action when they are placed together in a spring unit, and which can be easily aligned. An evolution of the offset coils brought the elimination of the knot that tied the end of the wire to the coil. In other words, offset coils might be tied off or feature a loose end (sensory arm). These are called "open end offset coils". These improvements gave offset coils an extra turn of working wire for greater spring action on each end of the coil.

Continuous coil

They look like double wire spirals or loose ringlets, creating a network of wire running nonstop through the entire bed. The brand Serta uses continuous coils in their mattresses. Kingsdown also uses such a system. The idea is that with a continuous coil system, each coil is connected to the next so that it can draw strength from it. This type of coil system does tend to be the strongest, however we must remember that strength does not dictate support.

Foundations

Although in the past the foundation actually contained springs, increasingly today it functions primarily to elevate the mattress, although a good box spring can help prolong the life and comfort of the mattress. There are three main types of foundations:

Traditional wood foundation

It is usually made of pine or similar hard wood. It usually has seven or eight support slats, covered with cardboard or beaverboard. This type of foundation, called by the industry a zero deflection unit, increases the feeling of firmness or stability.

Box spring

It features extra-heavy-duty springs. If the springs match the mattress it is called a coil upon coil box spring. Since a box spring has coils, it generally increases the give in the mattress, which in turn produces a softer or bouncier feel. Today, the boxspring is all but extinct. Research showed that boxsprings had too much give to them and caused coiled mattresses to sag prematurely. Most mattress manufacturers have switched to a rigid foundation with little or no fluctuation. By doing this and putting a high density block foam directly underneath the coils, the mattresses last longer.

Grid foundation

It is a combination of steel and wood.

Upholstery layers

The mattress core is covered by several soft materials, providing cushioning and comfort. Some manufacturers call the mattress core by the name "Support layer" and the cushioning materials by the name "Comfort layer". The "Comfort layer"can be divided into three sub-layers — Insulator, Middle Upholstery and Quilt. Aside from the number and gauge of the coils, the upholstery layers are used to differentiate the different "qualities" of mattresses that manufacturers produce.

Insulator

This layer separates the mattress core from the upholstery, and it is usually made of fiber or mesh, with the intention of keeping the middle upholstery in place.

Middle upholstery

The middle upholstery comprises all types of materials on top of the insulator and beneath the quilt. It is usually made from materials that give maximum comfort — regular foam, visco-elastic foam, felt, polyester fibers, cotton fibers, convoluted (or egg-crate) foam, non-woven fiber pads, etc.

Quilt

The quilt is a top layer of the mattress made of light foam or fibers stitched to the underside of the ticking, and provides the immediate soft texture that the user feels when lying on a mattress. The quilt can be firm or soft and plush. The protective fabric cover, which encases the support and comfort layers of the mattress, is called ticking. It is usually made to match the foundation and comes in a wide variety of colors and styles. Most ticking is made of synthetic fibers like polyester, latex and acrylic, or of natural materials such as cotton, silk & wool. The ticking produces the look and feel of the mattress, so it is usually soft to the touch and attractive to the buyer (at least that is what manufacturers intend to create).

Choosing a mattress

There are many different parameters that determine which is the best mattress for you. For some of these parameters, such as pressure distribution, skin microclimate, hygeine, edge support, and long-term stability, laboratory test methods have been established. Many of these have been developed by Dr Duncan Bain, working for The UK's Medicines and Healthcare products Regulatory Agency (see external link). The purchaser of a new mattress should ask to see manufacturer's documentation of independent evaluations conducted on their products, using these techniques.

Other parameters, such as comfort, and contribution to back pain, are more subjective.

Testing a mattress

The prospective buyer should lie on it for at least ten minutes, trying different positions.
Lying on the back — If a user slides his/her hand under the small of the back, and it is very easy and his/her shoulders and hips are uncomfortable, the mattress is too hard. If there is no space between the user's back and the bed, it's too soft.
Rolling over — If it takes a lot of effort, then the bed is too soft. If it is uncomfortable for the user's hips and shoulders, it's too hard.
The user should test the mattress on the type of base that it will be used on.
If the bed is for two people, both users should try it at the same time.

What to look for

The mattress should be designed to conform to the spine's natural curves and to keep the spine in alignment when lying down.
It should have perimeter edge support. Usually, this will be a heavy gauge border rod, however, in some high end models, a high density foam encased spring unit will provide firmer edge to edge comfort and support.
It should be designed to distribute pressure evenly across the body to help circulation, decrease body movement and enhance sleep quality.
It should be designed to minimize the transfer of movement from one sleeping partner to the other. The Marshall coil and viscoelastic memory foam designs achieve this better than traditional coil systems.
On a same size mattress, more coils of a lower gauge (thinner) may give better support and last longer than fewer coils with a higher gauge (thicker). A good warranty, 15 years being the best, will ensure your lower count-higher gauge coil mattress is of lasting quality.

Firmer or softer

There are three main sleep positions — Back, stomach and side. During a night's sleep, most people use more than one position. The sleeping position determines which part of the body will interface with the mattress, which in turn determines the amount of stress to the body. Use of a pillow can also help provide additional support and take pressure off certain parts of the body. For example, when sleeping on the back, placing a pillow under the knees can take stress off the low back. When sleeping on the side, placing a pillow between the knees will help keep the spine in alignment.

It is a common misconception that a "firm" or hard mattress provides better support. Doctors used to say that when they were rather oblivious about people's sleep habits and thought that everybody slept on their back 100% of the time. Now that we know that a majority of Americans sleep mostly on their side, further research tells us that a mattress that conforms better to the shape of the body provides better support.

Firm preference

Orthopedic doctors tend to recommend a firm mattress because it will not allow back or stomach sleepers to sag into the surface at unnatural angles. Air, water or foam mattresses are not generally recommended because they do not provide this level of support.
Stomach sleepers probably need a firmer mattress to prevent spinal distortion that can result in back pain when waking up.
It is easier to soften up a firm mattress with the proper padding or bedding, than it is to firm up an overly soft one that is causing a backache. However, firm mattresses are designed to feel hard, so even when adding padding to a firm mattress it will not feel like a soft one, because the body will sink through the foam onto the hard surface underneath. A firm or very firm bed might be topped with a three-inch viscoelastic foam pad giving the user the best of both worlds — Good support and soft cushioned feel.

Soft preference

Side sleepers usually face the greatest amount of weight on the smallest areas of the body thereby creating pressure points, which reduce circulation and can be a cause of the tossing and turning during sleep. A side sleeper will probably want a softer mattress, to minimize pressure points, especially if they have a very curved or rounded figure.
A study of sleep quality and bed firmness showed that four of nine male subjects slept significantly better on softer mattresses and two on the harder mattresses. Another study of 313 adults with chronic lower back pain showed that those who slept on a medium firm mattress experienced less back pain than those who slept on a firm mattress[link].

Not firm nor soft

Back sleepers need a mattress that offers enough support to fill in the gaps in the contour of the back, while at the same time providing enough comfort(according to the user's preference).

Firm AND soft

The brand Simmons currently produces King and Queen sized mattresses with a softer side and another firmer side, for the different tastes of the sleeping partners. Furthermore, there are mattresses that inflate and deflate inner air chambers to make the mattress harder or softer, with separate controls and air chambers for each side to allow it to adjust to the different comfort preferences of the sleeping partners.

Fluff and sag

Fabric is the most expensive element of mattress construction. Wool, silk, foam and cotton all increase the cost of the mattress. Thick layers of padding are more likely than the springs to compress to the point of feeling like the mattress is sagging. The fabric, foam or cotton eventually become concave because thick plush or pillowtop components eventually break down even if the springs do not. Unlike an eggcrate or other forms of padding, the mattress inner components cannot be removed and replaced when damaged.

Size

In the United States Twin and Double/Full/Matrimonial size are 75-78 inches long, depending on manufacturer. Queen and King are 80 inches long. "California" sizes, such as California King are 84 inches long. Extra Long sizes take the length to 80 inches. See Bedding for more sizes. A mattress should be at least six inches longer than the tallest person who will be sleeping on it.

Maintenance and care

A new mattress should be put on a firm base, never on a saggy base.
Most manufacturers of box spring mattresses suggest that the consumer should regularly rotate and flip the mattress and box spring. Otherwise, they caution the mattress will fail. Most manufacturers recommend to rotate the mattress (180 degrees, so the head of the bed becomes the foot) every three months and to turn the mattress at least twice a year. Some manufacturers recommend to alternately turn and flip the mattress once every two weeks for the first three months and then twice per year after that. The foundation should also be turned every 12 months. Mattresses should be rotated to reduce wear patterns over time. Since around 2000, several manufacturers started producing one-sided mattresses that cannot be flipped, and, in some cases, should not be turned.
Do not wet a mattress. An impermeable mattress protector can be used to keep it clean.
A vacuum cleaner can be used for regular cleaning.
Use a mattress pad to keep the mattress free from stains. If stained, use mild soap with cold water and rub lightly. Do not soak a mattress or foundation.
If a mattress has handles, they are usually only for positioning it, not carrying it. See your owners manual.
A Spring mattress should not be folded or bent, as is can be permanently damaged.
Sitting on the same spot of the mattress edge can permanently depress it.

Trivia

In Life, the Universe and Everything by Douglas Adams, mattresses are "... large, friendly, pocket-sprung creatures which live quiet private lives in the marshes of Squornshellous Zeta. Many of them get caught, slaughtered, dried out, shipped out, and slept on. None of them seem to mind and all of them are called Zem." Very few mattresses actually come back to life and attack the sleeper. See Races and Species in The Hitchhiker's Guide to the Galaxy

United States law requires all new mattresses, pillows, upholstered chairs, and similar stuffed articles to be sold with a tag describing the fabric and filling. The tag previously read "Do not remove under penalty of law", causing some consumers to believe that they could be arrested for cutting it off. The wording has since been changed to reflect that it is legal for the consumer to remove the tag of a mattress that they have purchased. [link] The industry term for the tag is a Law label. Some states require tags on used bedding as well. [link]

Glossary

Air Bed
Bed Frame or Bed Base/Frame
Bed Rails
Body Impressions
Bonnell Coil
Border Rod
Box Spring
Bunkie
Bunkie Board
California King
Cambrick
Center Rail
Channel Quilt
Clipped Border Rod
Coil Count — Number of coils in the mattress or box spring.
Coils
Comfort Layers
Cone-Shaped Coil
Continuous Coil
Continuous Quilt
Cover
Crown — Convex surface that is higher in the middle than in the sides; used in some mattresses.
Cushioning
Damask Cover
Density — It is a measure of weight and it is unrelated to firmness. It is the most significant factor in the quality of a foam and a very significant factor in the quality of a mattress. The higher the density, the longer the durability and resilience and support of the mattress.
Double Bed
Double Extra Long
Eliocel
Fatigue
Felt
Fiber
Filler
Firmness or Surface firmness — Resistance to compression near the surface of a mattress. It is measured by the surface Indentation Force Deflection (IFD) measurement. Deep down firmness is the IFD under severe compression.
Flanging
Flipping/Rotating
Foam — Padding material used in mattresses, including latex, polyurethane and viscoelastic or memory foam.
Foundation
Full Extra Long
Garnetting
Gauge
Grid
Helical Wire
Hinged King
Hog Ring
ILD — Initial Load Deflection. A measure for the firmness level of foam.
Inner Quilt
Inner Tufting
Innerspring Unit
Insulator
King
Knit
Lacing Wire
Latex
Law label: Term used by the United States mattress, upholstery and stuffed article (eg: pillows, plush toys, Comforters, etc) industry for the legally required tag or label on new items describing the fabric and filling. Typically these tags begin with a phrase such as This tag may not be removed under penalty of law except by the consumer. Some states require tags on used bedding as well.
Mattress
Mattress Handles
Migration
Multi-Needle Quilt
Offset Coil
Platform Foundation
Pillow Top
Pocketing
Posturized
Pressure Points
Queen
Quilting
Resiliency — Ability of the spring, foam, fabric or fiber to spring back to its original form. It is also known as bounciness or elasticity.
Ride — Reserve "springiness" and ease of vertical movement that a mattress has when a user is lying on it. When sleeping, the user's body moves subtly with every breath. A "bottomed out" mattress doe not easily move with the sleeper, causing aches after some time.
Roll-Together — When a defective or worn out mattress sags in the center and causes the body of the sleeper to want to roll towards the center of the mattress.
Rotating — Turning a mattress 180 degrees so that the head of the bed becomes the foot.
Sagging
Slats
Smooth Top
Split Queen Box
Spring Wire
Support
Support factor — Ratio of the deep down IFD to the surface of a mattress. Very important measure of the resistance to bottoming out under sustained downward pressure.
Tack and Jump
Tape edge or Mattress tape — It is a special fabric used to hide the seam where the pieces of ticking are sewn together. It works best when it provides a seamless and coordinating finish to the mattress.
Tempering/Stress Relief
Thermally-Bonded Cotton
Topper Pad
Twin
Twin Extra Long
Tufting
Upholstery Layers — This includes all the soft layers of a mattress, such as insulators, covers and quilts.
Ventilator
Viscoelastic foam

External links

From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.

International Mattress Sizes (Dimensions in inches. 1 inch = 25.4 mm)
Denomination	USA & Canada	Europe (UK)	Asia (Thailand)
Twin/Single	39 × 75	36 × 75	42 × 78 × 22
Twin/Single XL	39 × 80
Double/Full	54 × 75	54 × 75	48 × 78 × 22
Double/Full XL	54 × 80
Queen	60 × 80
Olympic Queen	66 x 80
California Queen	60 x 84
King	76 × 80	60 × 78	72 × 78 × 22
California King	72 x 84
Super King		72 × 78