Glossary of Terms

We could talk all day about our crib mattresses but while all this terminology may be second-nature to us, we realize it’s not to you. The last thing we want to do is talk over parents’ heads, so we’ve compiled a glossary of common terms and a brief explanation so that there’s no confusion. You’ll be a crib mattress expert in no time. If you still have questions or can’t find the answer you’re looking for then call or shoot us an email and we’ll be happy to help.

This term refers to the properties of the vinyl cover in a mattress or a pad that can resist certain microbes. This term is regulated by the Federal government and the vinyl has to have certain characteristics in order to be categorized as “anti-microbial.” To this end, the vinyl must be submitted for testing in an independent lab to determine whether or not it can be legally labeled as “anti-microbial.”

This is the product that is used in the lamination process of vinyl, which gives the vinyl additional strength. (see: laminate) There are several commonly used backing materials. Among them are typar (bonded polyester filaments), a polyester scrim and a nylon scrim. Of the three, nylon is the strongest.

Mattresses are sewn together by using a product known as binding. In the crib mattress industry, there are two types of binding – vinyl and cloth. Each has its own qualities and drawbacks. Vinyl binding, which is normally found on less expensive units, is easy to clean. However, over time, it tends to get brittle and begins to crack. In most cases it will still keep the seams together, but is aesthetically unpleasing to the eye. Cloth binding is used on the better quality goods. Cloth is much stronger than vinyl binding. That it is why it is used exclusively in the adult industry. The downside of cloth is that it can be stained. However, most parents use a waterproof sheet over the mattress, which will prevent this staining from happening. On one of Colgate’s upper end crib mattresses, we use an anti-microbial binding in tandem with an anti-microbial cover. Although this is a vinyl binding, it is made of superior quality goods and is as strong as cloth. It also has the same anti-microbial properties as the cover used on the mattress.

This is a rounded piece of steel that runs the entire perimeter of the innerspring frame top and bottom. It is attached to the coils. A mattress with a border rod has greater edge to edge support. The heavier the gauge of the wire, the better the spring unit is. Nine (9) gauge steel is the adult standard for a border rod.

This is a process done during the production of steel wire. Carbon-tempering hardens the steel so that it will take longer to fatigue over the life of the mattress.

This refers to the amount of turns that a coil has measuring from the top of the coil to the bottom. The more turns there are in the coil, the stronger and more durable each coil is. Most mattresses range from 3 to 5 turns in the coils.

Wire is turned in a circular direction to produce a mattress coil. There are several types of coils used in crib mattresses – double cone coils, barrel coils and pillar coils. The heavier the gauge of steel, the better and more durable the unit is. (see gauge of steel)

Coir fiber is more commonly known as coconut hair. Coconut hair is woven into a pad and then impregnated with latex to make it flexible. Coir fiber is the most durable type of insulator pad. Very few mattress manufacturers in either the adult or juvenile mattress industry use it. Another common use of coir fiber are door mats because of its strength and durability.

This is a product that is nominally 28″ x 52″ which, by regulation, cannot exceed six inches in height. A standard crib sold in the United States will use this size mattress regardless of the manufacturer.

This refers to the layer or layers that are placed over the insulator pad on a mattress. The three most common cushioning materials used in crib mattresses are polyester, polyurethane foam and cotton felt. Better quality mattresses use as least two layers of cushioning.

This is a measurement of polyurethane foam. density refers to the weight of one cubic foot of foam. There are no industry standards for what is identified as “high density” or “super high density”. However, the greater the weight of the foam the better the mattress will be. Eight other characteristics of foam (e.g. resiliency, sag factor, tear factor, etc.) react proportionately as the density of the foam goes up or down.

Effective July 1, 2007 a new flammability standard titled CFR 1633 was put in place. The new standard requires a mattress to pass an open flame test. You can go to for more information.

This refers to the amount of pressure that is required to make an impression on the mattress. Since there are no industry “firmness” standards, it is purely a subjective rating. Infants, unlike adults, need a much firmer surface to aid in the development and growth of their large muscle groups and spine.

Wire is measured differently than most other items. With wire, as the number gets lower the thicker the wire is. For example, a 6 gauge border rod is heavier and has more steel than a 9 gauge border rod. Likewise, a 12.5 gauge coil is heaver than a 13.5 gauge coil. With steel, smaller is better.

This is a type of insulator pad that is used in mattresses. It is more durable than “rag pad” but not as durable as a “coir fiber” pad. (see: insulator)

This is a wire that is coiled like a curly-cue. It is wound through the top and bottom heads of the coils tying them altogether. For each row of coils, there will be a helical wire on top and on bottom running the entire length of the mattress connecting the coils. On the outer edges of the mattress, the helical wire is wrapped around the border rod and the coils. The helical wire is not to be confused as a “border wire.”

There is a crib mattress produced that has this type of coil system. They start with a long polyester sleeve and put coils into the sleeve. After each coil is put into the sleeve the sleeve is heat welded around the coil. At each end of the sleeve, the coil is attached to the border rod. These are the only two connections in relationship to the other sleeves of coils. A barrel coil is used in this mattress.

This is a product that completely wraps around the steel frame of an innerspring unit. There are several types of insulators used in the mattress industry. They are rag pad (aka shoddy pad), polyester, hard felt and coir fiber. There are two major purposes for the insulator. The first is to eliminate “coil feel.”And the second is to protect the soft cushioning materials from coming in contact with the steel spring unit. Once the insulator wears out the soft cushioning materials will slip down into the heads of the coils and the spaces between the coils. The end result of insulator fatigue is a lumpy mattress. There is another insulator know as a “Permalator”that is a wire mesh insulator. (see: Permalator for more details)

The process is known as “lamination.” In the crib mattress industry waterproofing the mattress cover is primary concern. A laminated cover is one that has at least one layer of vinyl and a backing material pressed into the vinyl. A double laminate has a layer of vinyl and a backing material. This cover is stronger than a single ply or a quilted cover. A triple laminate cover is the strongest cover used on a crib mattress. A triple laminate is a combination of two layers of vinyl pressed into a backing material.

This is a wire mesh insulator that is placed over the spring, but under the regular insulator pad. The wire is oil-tempered for flexibility. By using a Permalator (aka “flexalator”) the regular insulator pad does not have direct contact with the steel of the spring unit. This ensures both a firmer mattress and a longer lasting mattress.

This term refers to a mattress that does not have a border rod. (see: border rod) The edges of the mattress may or may not have a helical wire (see: helical wire) that runs the entire way on the long side of the spring unit. This type of spring unit is less expensive, and also offers very little support on the edges of the mattress.

This is the basis for an innerspring unit. There are three main types of spring units used in the crib mattress industry – a Bonnell unit, Holland unit and a Marshall unit. The Bonnell unit is the oldest configuration of a spring unit. It is also know as a ” 312″ unit. The reason for this designation is that the full size mattress (4/6 or double bed) had 312 coils. A twin had less and a queen and king had more. Obviously, crib units have less coils than a full size spring unit. The standard unit had a nine (9) gauge border rod and thirteen and one-half (13.5) gauge coils, with each coil having 5 turns. The coils used are double cone coils (hour glass). Over the years other spring units have been developed on this configuration both adding and subtracting coils and changing gauges of steel. The next unit is a Holland unit. This is a very sophisticated technologically advanced unit. The concept behind the Holland unit is that each area of a mattress has different requirements to provide maximum support. To this end, the Holland unit employs 6 different types of coil. There is a specific coil placed in each of the corners – called a “corner coil.” Between the corner coils on the short and long edges of the mattress are “edge coils.” These are all knotted coils. Because there are fewer coils sharing the load at the edge of the mattress these coils are made with 12.5 gauge steel. There are two sets of interior coils. The first set going from the outside in, are corresponding right and left hand turn coils. These are free-end offset pillar coils. The opposing turn (right and left) minimize mattress sway. The free-end offset coils provide a supple surface, but will firm up where there is greater weight. The firmness comes from the stacking of the coils on top of one another – hence the term pillar coil. These coils are 13.0 gauge. Finally in the center of the mattress, there are the same coils as mentioned in the previous paragraph, but the gauge of steelgoes to the standard 13.5 gauge. The Marshall unit is the least used spring unit in the crib mattress industry. This is the individually pocketed coil type mattress (see: individually pocketed coil). The design concept behind this unit is primarily for adult usage. Because each coil works independently of all the others, as one person moves about in the bed, the other person in the bed would not have the coils moving underneath them. The goal was to allow for movement on one side of the bed without disturbing the sleep of another person sleeping on the same mattress.

Some, but not all crib mattresses have some sort of venting system. There are two major types – side vents and eyelets. The side vents can be either stainless steel or brass. Usually there are two on the opposing long sides of the mattress. Eyelet vents are usually brass. They usually are a double layer around the entire perimeter of the mattress border. Vents have two functions in a crib mattress. The first is to allow for some airflow to keep the mattress fresh. The second is to allow the release of air if the infant is a “jumper.” (A jumper is a child that will stand on the edge of the mattress while holding the crib rail and jump up and down.) By releasing the air, the seams of the mattress will be placed under less stress.

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