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Textile Glossary

Definitions of textile testing, fibre, yarn and fabric terms, with links to related standards and laboratory instruments.

Absolute humidity

The mass of water vapour contained in a given volume of air, usually given in g/m³.

Absorption

The take-up of a liquid or gas into the interior of a material, e.g. a fibre drawing in water or dye.

Accelerated aging

Simulating long-term deterioration in a short time by intensifying conditions such as heat, light or humidity.

Acceptance number (c)

In acceptance sampling, the largest number of defective units in the sample that still allows the lot to be accepted.

Acceptance sampling

Taking and testing samples from a lot in order to decide whether the whole lot is accepted or rejected.

Acceptance testing

Testing carried out to decide whether a lot meets the requirements of a contract or specification.

Accuracy

How closely the results of a test method agree with the accepted true or reference value.

Acid content (felt)

Amount of acid present per unit mass of felt, usually expressed in milliequivalents.

Acromion

The bony tip of the shoulder blade at the top of the shoulder, used as a landmark in body measurement for sizing.

Adhesion

The ability of two different surfaces to stay bonded, e.g. cord or fabric to rubber, or a coating to its base fabric.

Air permeability

The rate of air flow through a unit area of fabric, perpendicular to it, under a set pressure difference.

Standards ASTM D737

Related instruments Air Permeability Tester

Animal fiber

Natural protein-based fiber of animal origin, such as wool, silk or hair.

Aqueous extract

The solution obtained by soaking a specimen in water, used for analyses such as pH or water-soluble matter.

Armhole

Opening in the body of a garment where the sleeve is attached or the arm passes through.

Armscye

The opening in the body of a garment into which the sleeve is set.

Assignable cause

A non-random, identifiable factor that causes variation in process or test results and can be corrected.

Attribute data

Data recorded only as presence or absence of a characteristic rather than a measured value, e.g. pass/fail.

Average fiber diameter

Arithmetic mean of many measured fibre diameters in wool and other animal fibres, used as a fineness indicator (µm).

Back coating

An adhesive layer applied to the back of a carpet to lock pile tufts and add dimensional stability.

Backing (carpet)

In pile floor coverings, the supporting structure holding the pile yarn, i.e. all layers other than the pile.

Backing fabric

The fabric layer into which pile yarn is inserted, or which is bonded to the back of a product for support, as in carpets.

Bast and leaf fiber

Natural fibres taken from the inner bark of plant stems (flax, hemp, jute) or from leaves (sisal).

Bast fibers

Fibers obtained from the inner bark layer of plant stems such as flax, hemp and jute.

Bath mat

An absorbent textile floor covering used in the bathroom.

Bath towel

Terry-woven product with hemmed or fringed ends, used for drying the body.

Batting

A filling material made of a continuous fibrous web formed by carding, air laying or similar methods.

Beam

A large roll on which many parallel yarn ends are wound for weaving or warp knitting.

Bedcovering

A textile product spread over a bed, such as a bedspread, quilt or blanket.

Bench marks

Marks put on a specimen to set the gauge length used in tensile or dimensional change measurement.

Bias

A constant or systematic error that shifts test results in the same direction away from the true value.

Bicomponent fiber

A fiber made from two chemically or physically different polymers combined in one filament.

Binomial distribution

The probability distribution of the number of occurrences of an event of fixed probability in a set number of independent trials.

Blanket

Unquilted bedding fabric intended mainly to provide thermal insulation.

Bleach

In textile care, a chemical product used to whiten, brighten and remove stains.

Blister

A local bulge on a bonded or laminated fabric where the layers have separated.

Boundary friction

Friction at very low sliding speeds where only a thin lubricant film separates the surfaces.

Breaking strength

Strength expressed as the force at which a material breaks in tension.

Breaking tenacity

Breaking force divided by the linear density of the specimen, e.g. in cN/tex.

Breaking toughness

Energy per unit mass needed to stretch a material to break, taken from the area under the force-elongation curve.

Standards ASTM D3822

Related instruments Single Fiber Tensile Tester

Bulk sample

A representative quantity drawn from bulk material, from which laboratory samples are prepared.

Bursting strength

The force or pressure needed to rupture a fabric by distending it at right angles to its plane.

Button

Disc or knob passed through a buttonhole or narrow opening to fasten two parts of a garment.

Cable twist

A construction of cord or rope in which each successive twisting stage is in the opposite direction to the previous one.

Standards ASTM D1423

Related instruments Yarn Twist Tester

Calibration cotton standard

Blended cotton samples with established reference fibre values, used to calibrate fibre testing instruments such as HVI.

Care instructions

Directions telling how to wash, dry, iron or dryclean a product without damaging it.

Care label

Permanently attached label giving washing, drying, ironing and dry-cleaning instructions for the product.

Care procedure

One or more steps such as washing, dry cleaning or ironing used to restore a textile product for further use.

Carpet

A textile floor covering, typically covering the floor area, other than those classed as rugs.

Chain sampling

Acceptance sampling plan in which the decision also takes into account results from preceding lots.

Change in surface appearance

For pile floor coverings, the overall visual change of the surface after traffic or simulated wear.

Chlorine bleach

A bleach that releases hypochlorite ions in solution, such as sodium hypochlorite.

Cleaning agent

A chemical compound or formulation used to remove soil and stains.

Coated fabric

A flexible fabric with a polymer layer (PVC, PU, rubber etc.) applied to one or both faces.

Coefficient of variation unevenness (CV%)

Yarn or sliver mass variation between short lengths, expressed as standard deviation divided by the mean, in percent.

Standards ISO 16549

Related instruments Yarn Evenness Tester

Cohesive force

The force needed to overcome fibre-to-fibre cohesion when a sliver or roving is drafted.

Commercial laundering

Washing, drying and pressing of textiles in commercial facilities, usually at higher temperatures and with stronger chemicals.

Commercial mass

The billing mass, calculated with agreed moisture regain and finish allowances.

Component (fiber)

Each of the distinct polymers making up a multicomponent (e.g. bicomponent) fiber.

Cone

A conical yarn holder, or the conical yarn package wound on it.

Continuous filament yarn

A yarn made of filaments of essentially unlimited length rather than staple fibers.

Cord

A twisted structure of one or more plied yarns or filaments, used e.g. to reinforce tyres.

Cord twist

Number of turns per unit length of the final twist that combines the plies into a cord.

Core-spun yarn

A composite yarn with a filament or strand at its centre wrapped by a cover of staple fibres.

Count (fabric count)

In woven fabric, the number of warp ends and filling picks per unit length, e.g. per cm.

Course

In knitted fabric, a row of successive loops running across the width.

Covered yarn

A composite yarn with a core (often elastane) wrapped or covered by an outer fibre or filament component.

Crimp

Waviness in a fibre or yarn, natural or induced by processing or by interlacing in fabric.

Crimp frequency

In man-made staple fibres, the number of crimps per unit length of the straightened fibre.

Crimp index

An indirect measure of the size of crimp in a crimped or textured yarn.

Crowfoot weave

A broken twill weave with a one-up, three-down interlacing pattern.

Crush

In pile floor coverings, flattening of the pile with loss of tuft shape caused by compression and fibre entanglement.

Curing (vulcanization)

Process in which rubber or a coating is cross-linked by heat and chemicals to gain stable properties.

Data transformation

Converting data to another scale, e.g. logarithm or square root, to suit statistical analysis.

Defect

An imperfection that departs from specification and impairs the product's appearance or performance.

Detergent

A cleaning agent used to remove soil during washing; standard reference detergents are used in fastness and shrinkage tests.

Dimensional change

Shrinkage or growth in length and width of a fabric after treatments such as washing, pressing or heat, given in %.

Dimensional stability

The ability of a material to keep its length and width under specified conditions such as washing or heating.

Dip (cord dip)

A chemical treatment (e.g. RFL) applied to tyre cord or fabric to improve its adhesion to rubber.

Direction of lay

The helical direction of the components of a yarn, strand or cord, designated S or Z.

Direction of twist

The direction of the helix in a twisted yarn, named S or Z after the letter whose centre stroke it matches.

Standards ISO 2061

Related instruments Yarn Twist Tester

Discrete variate

A variable that can take only countable values, such as the number of defects per metre.

Distortion

A visible shift or skewing of warp and weft yarns from their normal positions in a fabric.

Double stroke

In abrasion or flex testing, one cycle made of one forward and one return movement.

Draw texturing

Process in which a thermoplastic filament yarn is drawn and crimped (textured) simultaneously or in sequence.

Drawing

Stretching or attenuating a fiber strand or filament to increase its length per unit mass.

Eight-harness satin

A satin weave repeating on eight ends, with warp or filling floats dominating the face.

Elastomeric yarn

Yarn that can be stretched repeatedly to at least twice its length at room temperature and recovers quickly when released.

Electrostatic decay half-life

The time needed for the maximum static voltage induced on a textile to fall to half its value.

Electrostatic propensity

The capacity of a non-conducting material to build up and retain an electric charge, e.g. by friction or contact.

Elongation

The increase in length of a specimen under tension relative to its original length, usually in percent.

Entanglement

How far the filaments in a yarn are interlocked so they cannot easily be separated, as with air-jet intermingling.

Experimental error

Variation in results that is not explained by the controlled factors of an experiment and is treated as random.

Extractable matter

Non-fibrous material such as oils or finishes, other than water, that a specified solvent removes from a textile.

Fabric

Planar textile structure made of yarns or fibers by weaving, knitting or bonding.

Fabric dip

A chemical mix applied to tire cord or fabric to improve its adhesion to rubber.

Factor

A condition deliberately varied in an experiment to study its effect on the result, e.g. temperature or laboratory.

Fiber beard

In fibre length testing, the tuft of fibres caught by a comb and then straightened and paralleled.

Fiber birefringence

Difference between refractive indices for polarized light vibrating parallel and perpendicular to the fiber axis; indicates orientation.

Fiber cohesion

The resistance of fibers in contact with each other to being pulled apart.

Fiber length distribution

Table or graph showing how the fibers of a sample are distributed across length classes.

Filling bar

Woven-fabric defect appearing as a band across the width that looks different from the adjacent fabric.

Final twist

The turns per unit length in a component of a plied yarn or cord, as found in the finished structure.

Standards ASTM D1423, ISO 2061

Related instruments Yarn Twist Tester

Flame application time

In a flammability test, the period during which the test flame is applied to the specimen.

Standards ASTM D1230

Related instruments 45° Flammability Tester

Flame resistance

The property of a material that prevents, slows or self-extinguishes flaming combustion after exposure to a flame.

Flame retardant

A chemical that makes a textile harder to ignite or slows its burning.

Flame-retardant treatment

A process that adds flame retardants to a material to reduce its tendency to ignite and burn.

Flammability

The set of properties describing how easily a material ignites and how it burns.

Flexibility

Ability of a material to withstand repeated bending or flexing without cracking or rupture.

Floor covering

A flat material, thin relative to its length and width, used to cover a floor.

Foreign matter

Material not belonging to the fabric, such as stray fibres or debris, woven in or stuck to it.

Fundamental resonant frequency

In vibroscope fineness testing, the lowest frequency at which a tensioned fiber vibrates freely.

Grade

A quality class given to a fabric based on the number or severity of defects in a defined area.

Grading

The procedure of identifying and scoring fabric defects to assign the product to a quality grade.

Grease wool

Wool shorn from the sheep that has not yet been scoured and still contains natural grease and dirt.

Greige cord

Tire cord that has not yet received adhesive, heat or other treatment.

Greige goods

Fabric as it comes off the loom or knitting machine, before any bleaching, dyeing or finishing.

Greige thread

Sewing thread after final plying, before any dyeing or finishing.

Growth

An increase in one or more dimensions of a material; the opposite of shrinkage.

Hole

Fabric defect in the form of an opening caused by broken yarns or damage.

Ignition

Onset of combustion in a material; the point at which burning first starts.

Immature fibers

Cotton fibers with poorly developed cell walls, identified for example by swelling in sodium hydroxide.

Imperfection

A departure of a quality characteristic from its intended level; classed as minor or major according to severity.

Industrial yarn

High-strength continuous filament yarn used in technical products such as tire cord, hose and belting.

Inflator

In airbags, the device that generates and directs the gas used to inflate the cushion.

Initial modulus

The slope of the initial straight part of the force–elongation (stress–strain) curve, indicating initial stiffness.

Inspection

Examining fabric for defects and grading it against a specification.

Interaction

The situation where the effect of one factor on the result depends on the level of another factor.

Interlining

A textile placed between the outer fabric and lining of a garment to add shape, body or warmth.

Standards ASTM D1230

Related instruments 45° Flammability Tester

Ironing

Pressing with a heated hand iron moved over the fabric, sometimes with moisture or steam.

Knitted fabric

A fabric formed by interlooping one or more yarns.

Laboratory sample

Portion of material taken from the lot sample from which test specimens are prepared.

Laundering

Removal of soil from textiles using water and detergent, usually including rinsing and drying.

Lea

In cotton yarns, a 120-yard length unit; skeins of this length are used in the skein break test.

Length of lay

The axial length over which one element of a cord or strand makes one full turn.

Lengthwise direction

The direction in a machine-made fabric parallel to the warp yarns.

Leno weave

Weave in which pairs of adjacent warp yarns cross around each other between picks, giving an open, stable fabric.

Level pile

Carpet pile in which all tufts are of practically the same height.

Long float

Weaving defect where a yarn passes unbound over more crossing yarns than the weave requires.

Loop pile carpet

Pile floor covering in which the pile yarns are left as uncut loops.

Loop-breaking force

The breaking force of two lengths of yarn or thread looped through each other and pulled in tension.

Lot

In acceptance sampling, a quantity of material assumed made under uniform conditions and judged as one unit.

Lot sample

Shipping units selected at random to represent the lot under acceptance.

Lot sampling unit

A unit such as a carton, roll or package taken from a lot for sampling purposes.

Major imperfection

In fabric grading, a clearly visible defect serious enough to cause the product to be downgraded.

Mature fibers

Cotton fibres that show a sufficiently thick cell wall when swollen in sodium hydroxide.

Median

The middle value of a set of observations arranged in order of size.

Micronaire

Relative measure of cotton fiber fineness and maturity based on airflow resistance of a fiber plug.

Minor imperfection

In fabric grading, a deviation that is not expected to materially affect use or performance of the product.

Missing yarn

Woven-fabric defect where a warp or weft yarn is absent from its intended position.

Mode

The most frequently occurring value of a distribution; for continuous data, the peak of the frequency curve.

Modified grab test

A tensile test gripping only the centre of the fabric width, with sideways yarn slippage reduced by cutting.

Moisture equilibrium for testing

The state where a specimen in the test atmosphere no longer changes mass noticeably because moisture exchange has stabilised.

Standards ASTM D1776

Related instruments Climatic Conditioning Chamber

Multilevel pile

Carpet pile in which some tufts are clearly higher than others, creating a patterned surface.

Nonconforming item

An item that fails to meet one or more specified requirements.

Nonconformity

Failure of a product or characteristic to meet a specified requirement.

Nonwoven fabric

A textile structure made by bonding or interlocking fibers mechanically, thermally or chemically, without weaving or knitting.

Parameter

In statistics, a fixed quantity describing a population, such as its mean or standard deviation.

Percent elongation

The increase in specimen length expressed as a percentage of its original length.

Permanent care label

A care label that stays legible and attached to the product for its useful life.

Pile floor covering (carpet)

Floor covering in which pile yarns are bound at intervals to a backing, the pile forming the use surface.

Pile yarn mass

The mass of pile yarn per unit area of a carpet, usually in g/m².

Polymer

A macromolecular substance built by chemically linking identical or different monomers; the raw material of synthetic fibres.

Precision

Degree to which repeated measurements on the same material agree with one another.

Primary backing

In tufted floor coverings, the base fabric through which needles insert the pile yarn to form tufts.

Probability function

A mathematical expression describing how probability is spread over the values of a continuous variable.

Professional care

Cleaning of textile products by trained staff with special equipment, e.g. professional dry or wet cleaning.

Pulled wool

Wool removed from the skins of slaughtered sheep, typically after chemical or sweating treatment.

Raised fiber surface

A fabric surface on which fibres have been deliberately lifted, e.g. by napping or sanding.

Standards ASTM D1230

Related instruments 45° Flammability Tester

Random sampling

Sampling method in which every unit of the population has an equal chance of being selected.

Randomized block experiment

An experimental design where similar units are grouped into blocks and treatments are assigned randomly within each block.

Raw wool

Sheep's wool as shorn, still containing grease, suint and dirt.

Recycled wool

Wool recovered as fiber from previously spun, woven or knitted products.

Reference standard

A homogeneous lot of material with known property values, used to calibrate and check instruments.

Refractive index

The ratio of the speeds of light in two media; used with microscopy to identify fibres.

Reinforcing cord

A cord made from industrial yarns that adds strength to products such as tires, hoses and belts.

Rejection number

In acceptance sampling, the smallest number of nonconforming units or defects that leads to rejection of the lot.

Relative density

The mass of a volume of material divided by the mass of the same volume of water.

Replicate

One of several repetitions of a test under the same conditions, used to assess repeatability.

Residual torsion

The number of turns a length of cord makes on its own when one end is fixed and the other is free to rotate.

Resistance to delamination

The force per unit width needed to separate the secondary backing from the rest of a floor covering.

Rotation (abrasion tester)

One count on the abrasion tester counter, roughly equal to one rubbing cycle.

Roving

A loose bundle of parallel fibers or filaments with little or no twist; in glass fiber, many strands gathered together.

Standards ASTM D4120

Related instruments Cohesion Tester

Ruggedness test

A planned experiment checking how much small changes in test conditions affect a method's results.

Sample

A portion of material taken from a lot to represent it, from which test specimens are prepared.

Sampling plan

A procedure stating how many units to take from a lot, how to select them, and how to decide acceptance.

Sampling unit

An identifiable, discrete unit selected during sampling, e.g. one roll of fabric.

Secant modulus

The slope of the line from the origin to a chosen point on the force-elongation curve; chord modulus is preferred.

Standards ASTM D3822

Related instruments Single Fiber Tensile Tester

Secondary backing

Additional fabric laminated to the back of a carpet to improve dimensional stability and strength.

Sensitivity

The ability of a test method to detect small differences in the property being measured.

Sewing thread

A fine, flexible yarn, usually lubricated or coated, made to sew smoothly through fabric.

Shrinkage

A reduction in one or more dimensions of a material, usually measured in percent after washing or heat.

Single twist

Amount of twist in each individual single yarn that makes up a plied yarn or cord.

Standards ISO 2061

Related instruments Yarn Twist Tester

Snagging resistance

Resistance of a fabric to pulled yarns and loops when caught by sharp or rough objects.

Soiling

The process by which dirt and foreign matter attach to a pile surface, such as carpet, and change its appearance.

Specification

A precise document stating the requirements a material or product must meet and how compliance is verified.

Specimen

The particular piece cut from a laboratory sample and tested to give a result.

Spot and stain removal

A cleaning step that removes localized spots and stains from a textile using suitable agents.

Stain

An area of discolouration that has penetrated the material and is hard to remove.

Standard atmosphere for testing

Controlled air conditions of specified temperature and relative humidity used to condition and test specimens (typically 20 °C, 65 % RH).

Standards ASTM D1776

Related instruments Climatic Conditioning Chamber

Standard atmosphere for testing textiles

Controlled conditions of temperature and relative humidity for conditioning and testing textiles, commonly 20 °C and 65 % RH.

Standards ASTM D1776

Related instruments Climatic Conditioning Chamber

State of statistical control

Condition in which process variation comes only from random causes, so results are predictable.

Stitch

In sewing, one repeating unit formed by the interlacing of sewing thread with itself or with the fabric.

Stitch type

A numerical designation describing the structure of a stitch (e.g. 301 lockstitch, 401 chainstitch).

Stitching

A series of stitches formed in or through a material.

Strength

A material's ability to resist deformation and rupture under applied force.

Systematic sampling

Selecting units at fixed intervals after a random starting point.

Tabby (plain weave)

The simplest weave, in which each weft passes alternately over and under successive warp yarns.

Tack

The ability of unvulcanised rubber or rubber compound to stick to a surface under light contact pressure.

Tare

The mass of packaging and wrapping material subtracted from the gross mass to find the net mass of the material.

Tensile strength

Maximum force a material sustains in a tensile test before rupture, per unit width or cross-section.

Test beard

In cotton length testing, the parallelised fibre tuft projecting from the clamp, on which measurement is made.

Test result

The value obtained by carrying out a test method in full, as one reading or an average of several.

Test specimen

Piece prepared from the laboratory sample on which the test is actually performed.

Textile floor covering

A product whose use surface is textile material, used to cover floors (carpets, rugs etc.).

Thermal shrinkage

Shortening of a yarn or cord caused by exposure to heat, expressed in %.

Thermal shrinkage force

The force generated by a material that is held so it cannot shrink when exposed to heat.

Thermal shrinkage force tester

An instrument that measures the shrinkage force developed by a yarn or cord held at fixed length while heated.

Tolerances

The permitted upper and lower limits of deviation of a property from its nominal value.

Top

A combed sliver with parallel fibres in worsted processing; also a sliver of cut man-made fibre.

Standards ASTM D4120

Related instruments Cohesion Tester

Top stop (zipper)

Part fitted at the top of the zipper chain that stops the slider from running off.

Tuft

A cut or uncut pile loop forming the face of a floor covering and anchored to its backing.

Tufted fabric

A pile fabric made by needling yarn into a pre-made backing fabric to form loops or tufts.

Underlay

A resilient layer laid under a carpet or rug to add comfort and extend its service life.

Uniformity ratio

In cotton fibre length testing, the ratio of mean length to upper-half mean length.

Upholstered furniture

Seating or reclining furniture covered with padding and upholstery fabric.

Variables data

Data from measurements on a continuous scale rather than pass/fail counts.

Vulcanization

An irreversible process in which rubber is cross-linked, e.g. with heat and sulphur, to become elastic and durable.

Wale

One of the raised ribs running warpwise in a woven fabric, as in corduroy.

Weftless fabric

Sheet of parallel cords with no weft yarns, used in tire building.

Widthwise direction

The direction across the fabric from edge to edge, perpendicular to its length; the weft direction in woven fabric.

Standards ASTM D5735

Related instruments Fabric Tensile Strength Tester

Wool

The natural protein fibre from the fleece of sheep.

Working cotton standard

Reference cotton sample used within a laboratory for routine calibration and comparison.

Yarn

A continuous strand of fibres or filaments suitable for knitting, weaving or other fabric forming.

Standards ASTM D1422

Related instruments Yarn Twist Tester

Yield strength

The force at which a material departs by a set amount from proportional stress-strain behavior and begins to deform permanently.