Chemical Hair Services: Color, Lightening, Waving, and Relaxing
Color Fundamentals
The pH scale runs 0-14; hair and scalp sit near pH 4.5-5.5, and all color and lightener products are alkaline, lifting the cuticle to deposit or remove pigment. The law of color: primary colors blue, red, yellow form secondary and tertiary colors, and complementary colors neutralize each other. Level runs 1 (black) to 10 (lightest blonde); tone describes warm, cool, or neutral. Hydrogen peroxide developer is stated by volume and percentage: 10 volume is 3 percent, 20 volume is 6 percent, 30 volume is 9 percent, and 40 volume is 12 percent. Volume drives lift and deposit, and mixing ratio follows the manufacturer - usually 1:1 for color, 1:2 for high-lift blondes.
Testing and Assessment
Always perform a patch test 24-48 hours before an aniline derivative color, and a strand test to preview timing and result. Assess porosity and elasticity: highly porous hair grabs color quickly and fades fast; poor elasticity means damage and a service refusal or restructure first. Record formulas.
Waving and Relaxing
Permanent waves use ammonium thioglycolate (alkaline) or glyceryl monothioglycolate (acid) to break disulfide bonds, then a neutralizer rebuilds them in the new shape. Relaxers use sodium hydroxide (lye, high pH) or guanidine/ammonium-based no-lye systems to straighten; hydroxide relaxers are not compatible with thio products on the same hair, and relaxing over a fresh wave (or the reverse) risks breakage.
Traps and Rule of Thumb
Questions confuse volume with percentage, claim developer adds color, or present a neutralizer as shampoo. Rule of thumb: developer decides lift; the tube decides tone.