Ever feel like products just sit on top of your hair, or conversely, that your hair “drinks” moisture and is still dry ten minutes later?
That’s porosity at work. It describes your hair’s ability to absorb and retain moisture, and quite frankly, it might be the most important trait you aren’t talking about. While curl type gets all the glory in the press, porosity is the workday habit of your hair that actually dictates the results. It’s the difference between a routine that works and one that feels like a constant battle against physics. As dumb luck would have it, many of us spend years applying heavy greasepaint to a complexion that needs a light-refracting serum.
Understanding if your cuticles are tightly bound (low) or open (high) is the secret to choosing the right oils, sealants, and water temperatures. High porosity hair is like orthochromatic film—it absorbs everything quickly, but because the “film” is so sensitive, it can’t hold onto the color (or moisture) for long. The surface layer cracks when your expression changes, leaving your curls looking ruddy and dirty. Low porosity hair, on the other hand, is like a fortress; you need heat and specific “Flexible Greasepaint” equivalents to even get past the gate.
The Porosity Spectrum
Low porosity hair often feels “product-heavy” because the cuticles are drawn straight, bold, and very long—think Louise Brooks—preventing anything from penetrating. Medium porosity is the industry standard, the “cupid’s bow” of hair health that takes moisture well and holds it with ease. Then there’s high porosity, often the result of debauchery in the form of over-processing, which requires heavy butters and cold-water rinses to “lock” the door. It’s like insurance for your hair; you’re doubling your wearability by ensuring the moisture stays where it belongs.
A Final Note
In the early ‘30s, Max Factor created a slick lip coat that became “X-Rated” lip gloss. High porosity hair needs that same level of high-shine sealing. Whether you’re using an Evian Mineral Water Spray to dampen your strands before a cream base or swiping with a wet powder sealant, the technique-specific category isn’t just a ploy to get you to buy more product. It’s about the glow. Once you master this technical shift, your hair will finally capture the incandescent incandescent light of a Hollywood set. Something I think we’re all still kind of into.
—Lauren Maas