Hair Porosity Quiz

Each answer scores 0, 1 or 2 points. An answer that points to low porosity scores 0, a middle answer scores 1 and an answer that points to high porosity scores 2. The six scores are added up. A total of 0 to 4 is low, 5 to 7 is medium and 8 to 12 is high. If you gave at least two low answers and at least two high answers, the result also tells you your answers were mixed.

In hair care, porosity means the degree to which water and other substances get into the hair fibre. Low porosity hair is described as slow to take in water and products. High porosity hair is described as taking them in quickly, and people who have it often say it also dries out quickly. These three groups are a hair care convention. There is no agreed cut-off between them.

Damage raises porosity. In published lab studies, bleached hair took up more dye than untreated hair, and ultraviolet light raised porosity further the longer the hair was exposed. Bleach and chemical relaxers also changed how water wets the surface of coily hair. Heat is usually blamed as well, but in one of those studies repeated blow drying and flat ironing did not change how water wet the hair surface, so the quiz gives chemical treatment and sun the same weight as each question about how your hair behaves.

The float test, where you drop a strand in a glass of water and watch if it sinks, is not a validated test. We found no published study that checks it against a lab measurement. A single strand is light enough to rest on the surface of water whatever is going on inside it, and oil from your scalp or leftover product on the strand changes how water wets it. Labs measure porosity in other ways, such as dye uptake, gas sorption or the angle a water drop makes on the hair.