Hair Coloring and Chemical Texture Services
This domain tests formulation logic: reading natural level and underlying pigment, choosing developer strength, predicting lift versus deposit, and controlling the reduction and re-bonding steps of texture services.
The level system and the law of color
Levels run 1 (black) to 10 (lightest blond). Eumelanin supplies brown-black pigment; pheomelanin supplies red-yellow. As you lift, warm pigment is exposed, which is why every formula above the natural level also needs a toning decision. Developer strength governs the outcome: 10 volume deposits, 20 volume lifts roughly one to two levels, 30 volume two to three, and 40 volume three to four with the most stress on the cuticle. Mixing ratios are manufacturer-specific, so read the label rather than assuming 1:1.
Texture services
Hydroxide relaxers straighten by lanthionization and need no neutralizer; thioglycolate relaxers reduce disulfide bonds and must be neutralized to rebuild them. Curl re-forming uses the same chemistry with a rod in place. Under-neutralizing shows up later as reversion.
Worked example
A natural level 5 client wants level 8. Reasoning: that is three levels of lift, so 30 volume is the realistic ceiling on the scalp, and the exposed warm underlying pigment must be toned. Apply to new growth first, then pull through the mid-lengths for the last few minutes, and never overlap lightener onto previously lightened ends.
Traps that cost marks
Reaching for 40 volume to force more lift; skipping the patch and strand tests; assuming gray hair is resistant without checking; forgetting that porosity changes processing speed; and treating relaxer and curl re-forming as interchangeable.