Cosmetology and Haircare Terminology

Density

Amount of hair strands growing per unit of scalp area.

Texture

Diameter/thickness of an individual hair strand; commonly fine, medium, or coarse.

Porosity (hair structure)

Hairs ability to absorb and retain moisture or chemicals.

Elasticity

Hairs ability to stretch and return to its original length without breaking.

Wave pattern

The natural configuration of the hair: straight, wavy, curly, or coily.

Growth pattern

Direction in which hair naturally grows.

Cowlick

A section of hair that grows in a different direction from the surrounding hair.

Whorl

Hair growing in a circular pattern around a central point.

Scalp disorder

An abnormal condition affecting the scalp.

Alopecia

Abnormal or excessive hair loss.

Pediculosis capitis

Head-lice infestation.

Nits

Eggs of head lice attached to hair shafts.

Psoriasis

Chronic skin condition that can cause raised, scaly areas on the scalp.

Dandruff

Excessive shedding of scalp skin flakes.

Follicle

The small structure in the skin from which hair grows.

Cuticle

The outermost protective layer of the hair shaft.

Cortex

Middle layer of the hair containing most of its strength, elasticity and pigment.

Medulla

Innermost layer of the hair shaft; may be absent in fine hair.

Elevation

Angle at which hair is lifted from the head before cutting.

Guideline

A section of hair used to establish the length or shape of a haircut.

Stationary guideline

Guideline remains in one location while subsequent sections are brought to it.

Travelling guideline

Guideline moves with each new section being cut.

Overdirection

Combing hair away from its natural fall before cutting to create length or weight.

Tension

Amount of pressure used to hold hair while cutting.

Distribution

Direction hair is combed or positioned before cutting.

Section

A subsection of hair separated for control during a service.

Graduation

Haircutting technique that creates a graduated buildup of weight.

Layering

Cutting technique that removes weight/creates shorter interior lengths.

Blunt cut

Hair is cut to one relatively solid length, creating a strong perimeter.

Texturizing

Removing or reducing bulk and/or creating movement without significantly changing the overall length.

Point cutting

Cutting into the ends of the hair with the tips of the scissors.

Slide cutting

Scissors are slid along the hair to remove weight and create softness.

Notching

Cutting into the hair to remove weight or create texture.

Perimeter

Outer edge or outline of a haircut.

Weight line

Visible concentration of weight in a haircut.

Natural level

The level of lightness/darkness of a persons natural hair.

Level

Degree of lightness or darkness of hair colour.

Tone

The underlying or visible colour characteristic, such as warm or cool.

Hue

The actual colour family, such as red, blue or yellow.

Undertone

The warm pigment exposed when hair is lightened.

Complementary colour

A colour opposite another colour on the colour wheel that can neutralize it.

Neutralization

Using an appropriate complementary colour to reduce an unwanted tone.

Deposit

Adding colour molecules to the hair.

Lift

Lightening the hair by removing or reducing natural/artificial pigment.

Oxidation (hair colour)

Chemical reaction involving oxygen; important in permanent colour and lightening.

Developer

Oxidizing agent used with certain colour products to activate them.

Volume (developer)

Strength/concentration of hydrogen peroxide in a developer.

Virgin hair

Hair that has not previously received a chemical colour service.

Regrowth

New hair growth between the scalp and previously coloured hair.

Porosity (hair colour)

Hairs ability to absorb and retain colour and moisture.

Colour correction

Process of correcting an undesirable colour result.

Filler

Product/service used to replace missing pigment before applying the desired colour.

Formulation

Selection and proportion of products used to achieve a specific result.

Strand test

Test performed on a small section of hair to predict the result or processing response.

Patch test

Test used to check for possible sensitivity/allergic reaction to certain products.

Permanent wave

Chemical service that restructures hair into a wave or curl pattern.

Reducing agent

Chemical that breaks disulfide bonds in the hair during permanent waving.

Disulfide bond

Strong bond in the hairs keratin structure that contributes to its shape and strength.

Reduction

Chemical process that breaks disulfide bonds.

Oxidation (chemical services)

Chemical process involved in reforming/stabil