Also known as cold waves; have a pH between 9.0 and 9.6, use ammonium thioglycolate (ATG, and process at room temperature.
Alkaline Waves
Perm wrap in which one end paper is folded in half over the hair ends like an envelope.
Bookend Wrap
Perm wrap that is similar to the double flat wrap but uses only one end paper, placed over the top of the strand of hair being wrapped.
Single Flat Wrap
Wrapping technique that uses zigzag partings to divide base areas
Weave Technique
Hair is wrapped at an angle other than perpendicular to the length of the rod, which causes the hair to spiral along the length of the rod, similar to the stripes of a candy cane.
End Papers
Perm activated by an outside heat source, usually a conventional hood-type hair dryer.
Endothermic Waves
Main active ingredient in true acid and acid-balanced waving lotions.
Glyceryl Monothioglycolate
Have a pH between 4.5 and 7.0 and require heat to process; they process more slowly than alkaline waves, and do not usually produce as firm of a curl as alkaline waves.
True Acid Waves
Perms that use sulfates, sulfites, and bisulfites as an alternative to ammonium thioglycolate; they have a low pH.
Low-pH Waves
Permanent waves that have a 7.0 or neutral pH; because of their higher pH, they process at room temperature.
Acid-Balanced Waves
Perms in which the hair strands are wrapped from the ends to the scalp on overlaying concentric layers.
Croquignole Perm Wrap
Create an exothermic chemical reaction that heats up the waving solution and speeds up processing.
Exothermic Waves
Perm wrap in which one end paper is placed under and another is placed over the strand of hair being wrapped.
Double Flat Wrap
Also known as piggyback wrap; a wrap technique whereby extra-long hair is wrapped on one rod from the scalp to midway down the hair shaft, and another rod is used to wrap the remaining hair strand in the same direction.
Double-Rod Wrap
Relaxers that require the application of protective base cream to the entire scalp prior to application of the relaxer.
Base Relaxers
A process of service that rearranges the structure of curly hair into a straighter or smoother form.
Chemical Hair Relaxing
Very strong alkalis with a pH over 13; the hydroxide ion is the active ingredient in all hydroxide relaxers.
Hydroxide Relaxers
Use the same ammonium thioglycolate (ATG) that is used in permanent waving, but at a higher concentration and a higher pH (above 10).
Thio Relaxers
Process by which hydroxide relaxers permanently straighten hair; they remove a sulfur atom from a disulfide bond and convert it into a lanthione bond.
Lanthionization
Ionic compounds formed by a metal (sodium, potassium, or lithium) which is combined with oxygen and hydrogen.
Metal Hydroxide Relaxers
Base control in which the hair is wrapped at 45 degrees below the center of the base direction, so the rod is positioned completely off its base.
Off-Base Placement
Base control on which the hair is wrapped at an angle of 90 degrees or perpendicular to its base section and the rod is positioned half off its base section.
Half Off-Base Placement
Stops the action of a permanent wave solution and rebuilds the hair in its new curly form.
Thio Neutralization
Conditioners with an acidic pH that restore the hair’s natural pH after a hydroxide relaxer and prior to shampooing.
Normalizing Lotions
An acid-alkali neutralization reaction that neutralizes (deactivates) the alkaline residue left in the hair by a hydroxide relaxer and lowers the pH of the hair and scalp; hydroxide relaxer neutralization does not involve oxidation or rebuild disulfide bonds.
Hydroxide Neutralization