Carpeting Glossary & Carpet Terminology

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Confused about an abbreviation or lost when trying to read carpet specifications?
Fear no more.
In this ultimate carpet glossary, you'll find the answers you need to interpret
the most important carpet terminology used around the world. 

This is the final chapter of The Ultimate Guide to Carpets.
Download the full guide here.
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Abrasive wear:

Wear or texture change to an area of carpet that has been damaged by friction caused by rubbing or foot traffic.


A carpet’s ability to dissipate an electrostatic charge before it reaches a level that a person can feel.

Attached cushion:

Padding, such as foam rubber or polyurethane,that is made as an integral part of the backing.

Average pile density:

The weight of pile yarn in a unit volume of carpet. It is expressed in ounces per cubic yard in the formula: Density = pile yarn Weight (in ounces per square yard) times 36 divided by pile Thickness or pile Height (in inches). Average pile density factors for commercial carpets range from 4200 to 8000.



The fabric and yarns that make up the side of the carpet that lays next to the floor. In tufted carpets there are two types of backing.

Primary backing:

A woven or nonwoven fabric through which the yarn is inserted by the tufting needles.

Secondary backing:

Fabric that is laminated to the back of the carpet to reinforce it.

Beck dye:

Dyeing of tufted greige carpet in a large vat of dye liquor. In this process, the carpet roll is sewn into a loop and then is continuously rotated and immersed in the heated vat for several hours. Most commonly used for cut pile carpet, it offers good custom colour flexibility.

Bound Carpet:

Carpet that is cut and bound (by stitching or serging around all sides) but not attached to the floor.


Broadloom carpets also known as wall-to-wall carpets, up to four and five metres width.



Carpet with casual cut pile construction featuring chunky tufts and long pile height. Carpet tile: Also called “modular carpet”. Generally 48 x 48, 50 x 50, 60 x 60 or 96 x 96 cm squares cut from broadloom carpet, but also available in other shapes and sizes.

Colour matching:

The proper coordination of colour and shade. Critical to colour matching are:

1. The light under which the colours are compared. (The light source being used in the real conditions of the commercial environment should be used to match colours).
2. The surface texture of the object being matched (cut pile carpet can appear darker than loop made of the same yarn).
3. The surface lustre of the object being matched (higher yarn lustre can look darker than lower lustre fibres).

Colour fastness:

The ability of a fibre or carpet to retain colour when exposed to  

1. Ultraviolet light,
2. Crocking (wet or dry) and
3. Atmospheric conditions (according to manufacturers’ and government test standards).

Commercial matching:

Matching of colours within acceptable tolerances or with a colour variation that is barely detectable to the naked eye.


The carpet manufacturing method, usually tufted, woven or bonded. The term also can refer to the specific details of a particular carpet’s specification, including fibre type, yarn twist level, density, method of dyeing, etc.

Conventional backing:

Carpet with a primary and secondary latex-laminated woven or nonwoven fabric.

Crock fastness:

The resistance of transfer of colourant from the surface of a coloured yarn or fabric to another surface, or to an adjacent area of the same fabric, principally by rubbing.


The removal of dye from a fabric by rubbing. Crocking can be caused by insufficient dye penetration or fixation, the use of improper dyes or dyeing methods, or insufficient washing and treatment after the dyeing operation. Crocking can occur under dry or wet conditions.


The collapsing of pile yarns, resulting in carpet matting and loss of resilience. This form of carpet failure usually occurs in the areas of heaviest traffic. It is also called “matting” and “walking out”. It can be minimised by the use of more resilient fibres, denser construction, somewhat higher weight and (in cut pile) with higher tuft twist and proper heat setting.


The material placed under a carpet for softness and support. It helps reduce noise, increases insulation benefits, and contributes to a softer feel underfoot. Purchasing an incorrect type of cushion may invalidate your warranty. Also known as padding or underlay.

Cushion-backed carpet:

Carpet having a cushion, padding or underlay material as an integral part of its backing.

Cut pile:

A carpet in which the yarn loops are cut to create a textured look and feel.

Pattern cut pile:

Made from saxony yarn, this carpet features a sophisticated look created by running cut pile and loop pile on a level pile height.



The metric equivalent to denier; equals the total weight in grams of 10,000 metres. Decitex is used in Canada and Europe.


A form of deterioration of tufted carpet in which the primary backing and face yarns separate from the secondary backing.


Synthetic fibres with polymer additives and/or cross-section design modification that limit its natural brightness or reflectivity. Delustring improves soil-hiding characteristics.


Denier is the amount of yarn per area of carpet.


Density refers to the amount of pile yarn per area of carpet or the closeness of the tufts. Higher density carpet improves resistance to crushing and matting.

Dimensional stability:

The ability of carpet to retain its size and shape once installed. Typically, dimensional stability is obtained in tufted carpet by the application of a secondary backing. In woven carpet, dimensional stability is normally provided by choosing stable backing yarns, especially the stuffer and filling, as well as by application of latex to the completed carpet.

Double-glued seams:

Double-glued seams attach carpet to bare floor to prevent delamination and edge ravel. Installers should double-glue seams to prevent fuzzing.

Drop match:

A drop match is a pattern that continues across the carpet diagonally or at a 45-degree angle to the edge of the seam.


A term applied to manufactured fibres that have been chemically or physically modified to reduce the brightness of the fibre. xtra heavy traffic: More than 10,000 traffics per day. Could also include some directional, nondirectional, pivoting and rolling traffic, as well as tracked-in dirt. See “Foot traffic units.”


Extra heavy traffic:

More than 10,000 traffics per day. Could also include some directional, nondirectional, pivoting and rolling traffic, as well as tracked-in dirt. See “Foot traffic units.”


Face weight:

Face weight is the number of ounces of fibre per square yard in the face of the carpet (not including the backing). The face weight affects performance and durability. Face weight is different from density because it varies with carpet height.


Loss of colour caused by sunlight or artificial light, atmospheric gases including ozone, nitrogen dioxide and hydrogen sulphide, cleaning and bleaching chemicals such as sodium hypochlorite, and other household and industrial products. Commercial installations in areas where such exposures occur require care in selection of colour-fast carpet.


Fibre is the fundamental unit of carpet. Carpet fibres are made from nylon, polyester, cotton, acrylics, wool, and recycled material.


Processing of carpets after tufting (weaving) and dyeing is called finishing. Processes include application of secondary backing, application of attached foam cushion, application of soil-resistant treatment, shearing, brushing, dyeing, printing and others.


A term used to describe a material that burns slowly or is self-extinguishing after removal of an external source of ignition. A fabric or yarn can be flame-resistant because of the innate properties of the fibre, the twist level of the yarn, the fabric construction, the presence of flame retardants or a combination of these factors.


Flocked carpet is made of tufts of wool or cotton fibre.


Loose fibre fragments remaining from the manufacturing process that appear on a carpet surface. This condition is remedied by vacuuming and carpet use; also known as “fuzzing” or “shedding”.

Foot traffic units:

One foot traffic unit is described as a pedestrian walking across a measured section of carpet, one time. Foot traffic is classified as follows:

Light Less than
Moderate Between 100-1.000/day
Heavy Between 1.000-10.000/day
Extra Heavy More than 10.000/day


Fusion bonding:

Fabrication of carpet for a 6” wide or modular tile. It uses a thermoplastic process that implants yarn in a liquid vinyl compound to two backing materials in a sandwich configuration. A knife splits the sandwich to create two carpets simultaneously. Spun yarn is used in this process, and only cut pile carpets are produced.

Fusion bonded carpets:

Backing material for fusion-bonded carpet is a system of layered vinyl or plastic compound and fibreglass scrim for dimensional stability.

For Tufted Carpets: 

1. Primary backing – In tufting, a woven or nonwoven fabric in which the pile yarn is inserted by the tufting needles. Usually woven or non-woven polypropylene for carpet. In the past woven jute was used.

2. Secondary backing – Fabric laminated to the back of carpet to reinforce and increase dimensional stability. Usually woven or nonwoven polypropylene.

For Woven Carpets:

Backings of woven carpets are the “construction yarns” comprising chain warp, stuffer warp, and shot or fill, which are interwoven with the face yarn during carpet fabric formation.


Fuzzing occurs when fluffy particles appear on carpet surfaces. It is caused by fibres that loosen because of weak twist or snags. Professional carpet cleaners can shear the carpet to remove fuzzing.



The distance between two needle points in knitted or tufted carpet. It is usually expressed in fractions of an inch.

Greige goods:

Pronounced “gray” goods. Term designating carpet in an undyed or unfinished state.


Hybrid carpet:

A carpet in which two or more different yarn types are combined in the carpet construction.


International Grey Scale for Colour Change:

A standard comparison to rate degrees of colour change from 5 (no change) to 1 (severe change).

International Grey Scale for Staining:

A standard comparison to rate degrees of staining from 5 (no stain) to 1 (severe stain).

ISO (The International Organization for Standardization):

A non-governmental, worldwide organization whose work results in international agreements that are published as International Standards.


Level loop:

The fibre in the carpet is stitched in uncut loops of the same size. It creates a smooth, level surface.

Light fastness:

The degree of resistance of dyed textile materials to the colour-destroying influence of sunlight.

Loop pile:

A tufted or woven carpet pile surface where the face yarns are comprised of uncut loops. Loop pile can be level, textured or multilevel.


Brightness or reflectivity of fibres, yarns, carpets or fabrics. Synthetic fibres are produced in various lustre classifications including bright, semi-bright, semi-dull and mid-dull. The lustre of finished carpet could also be influenced by yarn heat setting methods, dyeing and finishing. In high-traffic commercial areas, duller carpet yarns are often preferred for soil-hiding ability.



Matting is the usually irreversible adhesion of carpet yarn caused by traffic or dirt.


Carpet memory refers to texture retention.

Metameric colour match:

A colour match between two materials in which the colours are identical under some lighting conditions but not under others. Metameric colour matches are common when different pigments or dyestuffs are used to colour the two materials.

Multilevel loop pile:

A woven or tufted carpet style having tufts of varying pile heights, resulting in a sculptured appearance, pattern or subtle shading.


Needle punched:

Needle punched carpet is stitched into backing material.


1. Any carpet manufactured by a method other than weaving, but particularly those composed of fibres held together by chemical, mechanical, adhesive or fusion means.

2. Any primary backing material manufactured by a method other than weaving.

Olefin fibre:

Also known as polypropylene. Olefin is a lightweight fibre and can have good bulk and cover. However, the polymer base creates a soft fibre which has poor resiliency, a lower melting point and poor texture retention as compared to nylon. Only when budget is the main consideration, lower life expectancy is anticipated, and long-term appearance retention is not a priority, olefin can be considered.


Pattern match:

Lining up patterned carpet in such a way that the design element is continued across seams, making the finished installation appear cohesive. Patterns must be matched in the same way as they appear on the carpet itself either in a set match or drop match. 

Pattern streaks: 

Visually apparent streaking in patterned carpet resulting from linear juxtaposition of pattern elements in one direction. It is usually most visible in the length direction. It is not a carpet defect, but is inherent in certain designs. Contract specifiers should view rolls of carpet laid out on a floor to evaluate geometric or other busy patterns for this characteristic which may be unsuitable in long corridors and other large areas, but not visible in small rooms.

Patterned loop:

A woven or tufted carpet style having all tufts in a loop form in either a defined or random pattern or design.


The visible surface of a carpet, consisting of yarn or fibre tufts in loops that can be either cut or uncut. Also known as the “face” or “nap” of a carpet.

Pile crush:

Loss of pile thickness by compression and bending of tufts caused by foot traffic and heavy pressure from stationary furniture. The tufts collapse into the space between them. It may be irreversible if the yarn has inadequate resilience and/or the pile has insufficient density for the traffic load.

Pile height:

The length of the tufts measured from the primary backing top surface to their tips. Pile tufts should be gently extended but not stretched during accurate measurement.

Pile Reversal:

Pile reversal or shading is a feature of cut pile carpet. Traffic bends the carpet fibre in different directions creating an impression of light and dark areas. Regular vacuuming can create uniform shades.

Pile thickness:

The resulting thickness when the thickness of the backing is subtracted from the total thickness of the finished carpet. Pile weight: The weight in ounces of the fibre in a square yard of carpet.


A condition, often caused by heavy use, in which fibres from different tufts of carpet become entangled in one another forming hard fibre masses or “pills.” These pills can be cut off with scissors.


A cut pile carpet in which the individual carpet fibres appear to be cut the same length. The carpet offers a smooth, luxurious surface.


A measure of the number of individual yarns twisted together to produce the finished carpet yarn. For example, a two-ply yarn means that each tuft consists of two yarns twisted together. For cut-pile carpets, plied yarns must be heat set to prevent untwisting under traffic.

Power Stretcher:

A tool used to install broadloom carpet that prevents wrinkles and ripples.

Printed carpet:

Carpet having printed coloured patterns. Printing methods include flatbed screen printing, rotary screen printing, and modern computer-programmed jet injection printing.

PVC hard-backed or closed-cell PVC (polyvinyl chloride):

Used mostly in carpet tile or 6” wide goods due to its weight and stiffness. PVC gives a stiff, stable backing with little cushioning but excellent tuft bind and stability.


Random sheared:

A carpet texture created by lightly shearing (shaving off) either level loop or high-low loop so only some of the tufts are sheared. Shearing gives a cut and loop texture.


The distance from a point in a design in a patterned carpet to a point where the identical pattern appears again, measured length-wise and widthwise in the carpet. In matching the pattern, there will inevitably be some waste of carpet in order to obtain the best possible side match—whether it is a drop or set match pattern.


The ability of carpet to spring back to its original texture and thickness after being walked on or compressed by the weight of furniture. Also known as “resiliency.”


Heat and humidity can cause ruffles or waves in wall-to-wall carpet. A professional carpet retailer or installer can re-stretch the carpet with a power stretcher.



Apparent colour shade difference between areas of the same carpet caused by normal wear and/or random difference in pile lay direction. It is a characteristic of cut pile carpet. It is not a manufacturing defect.


New carpet tends to shed for a few weeks after installation. Regular vacuuming can resolve this problem. Shedding is more common in cut pile carpet and in wool carpet. Synthetic fibre carpet (such as nylon) does not shed as much.

Soil retardant:

A chemical finish applied to carpet fibres or surfaces that inhibits the attachment of soil.


The raising up of an individual tuft or fibre above the level of the pile. These may be cut with scissors. If the sprouts are large, however, call in a professional carpet cleaner, retailer or installer to resolve the problem.

Static control test:

A measurement of the amount of static discharge that occurs under specified conditions.

Static shock:

Build-up of electrostatic energy on a carpet and the subsequent discharge to a conductive ground such as a filing cabinet. Various static control conductive systems are used in commercial carpet to dissipate static charge before it builds to the human sensitivity threshold, which is 3.5kV.


The procedure for installing carpet over a separate cushion using a tackless strip with a power-stretcher.

Surface energy:

Technical measure of the tendency of a surface – in this case, the carpet yarn – to repel molecules of another substance. Low surface energy refers to a repelling action.


Texture Retention:

Texture retention or carpet memory is the ability of tufts to retain their shape under traffic.


A method of manufacturing carpet. Tufts of fibre are inserted through a carpet backing to create a pile of cut and/or loop ends.



Colloquial term for the synthetic polymer, polyvinyl chloride. Also called PVC. PVC is used as a carpet back-coating for carpet tiles and 6” goods. Vinyl foams have been used as attached cushions. Many walk-off mats have solid sheet vinyl backing.


Waterfall Installation:

Stairs are composed of a tread (the upper horizontal part of a step) and a riser (the upright member between two stair treads). Waterfall installation attaches carpet to two points on each step (one at the back of the tread and one at the bottom of each riser). This type of installation extends the life of carpet on stairs. When the carpet on the treads become worn, they can be taken up, reversed, and reinstalled with the worn areas placed over the risers. 

Woven backing:

A tufted carpet term for primary or secondary backing manufactured by the weaving process. Secondary backings are usually woven jute or woven polypropylene.

Woven carpet:

Carpet produced on a loom. Warp pile yarns intertwine with wires and backing yarns called warp yarns. These yarns are locked in with the weft yarns. Warp stuffer yarns are included to provide extra stability. Weaving is a slower, more expensive, labour-intensive fabrication method than tufting. Woven carpet is distinguished by intricate patterns and tailored, controlled textures.


Yarn count:

A number used to describe the size of the yarn. Denier is used for BCF yarns, and cotton count for spun yarns.

Yarn denier (bundle):

The total weight in grams of 9,000 metres of a filament yarn bundle. Common commercial carpet yarn deniers range from 1,200d to 5,000d.

Yarn ply:

The number of single fibres twisted together to form a plied yarn. Yarn weight: Total amount of yarn used in the manufacturing of carpet. It is measured in ounces per square yard.



A loop pile carpet in which tufts are pulled from the backing resulting in long, lengthwise pulls out of the carpet. Zippering occurs when the tuft base is not securely encapsulated by the backing compound.

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