Lightening and decolorization

"Lightening " is a course that covers two seemingly opposite processes: decolorizing dyed hair and pigmenting gray hair. They share a common denominator—working on hair without natural pigment, which requires a completely different approach than standard coloring. The course demonstrates how to strategically tackle the most challenging cases in the salon: from removing years of dark, store-bought dye to achieving 100% coverage of stubborn, glassy gray hair without creating a flat, dull effect.

Bartłomiej Lacz guides us through the chemistry and logic of both processes, from the structure of the hair to the action of specific ingredients in the mixture. He explains why a low-strength oxidizer and a longer bleaching time yield a cleaner result than a high concentration applied quickly, and when a 3% solution is sufficient to fully cover gray hair. On a flipchart, he visualizes how pigment precursors work in coloring and ammonium salts in the lightener, providing tools for informed work planning rather than just replicating formulas.

In this course, you'll learn:

• The true meaning of coverage percentages on paint – why 50% coverage won’t cover 30% of the gray hair on the head, and how this knowledge changes the choice of mixture.
• The principle of working with “fresh developer” – why mixing small batches every 15–20 minutes is the key to even bleaching from the nape of the neck to the crown of the head.
• The technique of adding golden pigment to cool-toned mixtures for gray hair to achieve luminosity and richness, rather than a warm tone.
• Why does henna decoloration result in green or turquoise highlights, and how does it fundamentally differ from removing oxidative pigments?
• When is a 3% oxidizer sufficient to cover 100% of gray hair, and when do you need to use a 9% oxidizer? The answer depends on the hair’s texture (glossy vs. dull).
• The difference between a pigment precursor and the pigment itself—and how understanding this process helps prevent insufficient coverage of gray hair.

After this course, you’ll stop treating decoloring and gray coverage as an unpredictable gamble. You’ll understand the chemical fundamentals of both processes, allowing you to consciously select the right products, timing, and techniques for each specific hair structure and its history. You’ll turn the salon’s toughest cases—from stripping black dye to stubborn gray hair—into opportunities to showcase your craft based on knowledge, not luck.