Normal is a term widely used to refer to well-balanced skin. The T-zone (forehead, chin and nose) may be a bit oily, but overall sebum and moisture is balanced and the skin is neither too oily nor too dry. No or few imperfections, barely visible pores and radiant complexion.
Oily skin is prone to comedones (blackheads and whiteheads) and to the varying forms of acne. Enlarged pores, dully or shiny, thick complexion and prone to blackheads, pimples or other blemishes.
Dry skin can crack, peel, or become itchy, irritated, or inflamed. If it’s very dry, it can become rough and scaly, especially on the backs of your hands, arms, and legs. Almost invisible pores, dull, rough complexion, skin is less elastic and more visible lines.
Combination skin can be dry or normal in some areas and oily in others, such as the T-zone (nose, forehead, and chin). Many people have this skin type. Pores that look larger than normal, because they’re more open, prone to blackheads and shiny skin
Comedogenicity is the tendency of an ingredient or product to clog pores. The comedogenic scale is ranked by how likely it is that any specific ingredients, such as oils and butters used in cosmetic product formulation, will clog pores. Anyone who is susceptible to acne breakouts and blackheads should avoid highly comedogenic oils, as they are likely to cause recurring acne problems.
A comedogenic rating of 0 is widely believed to be non comedogenic and will not clog your pores.
A comedogenic rating of 1 signifies a low probability that the product will clog your pores.
A comedogenic rating of 2 signifies that the product has a moderately low probability of clogging pores. It will not clog pores for MOST people, but some will begin to notice breaking out in some cases.
A comedogenic rating of 3 signifies a moderate probability of clogging pores. This is where a lot of people will break out using the product, but a lot of people may not break out depending on their skin type.
A comedogenic rating of 4 has a fairly high probability of clogging pores. This rating suggests that MOST people will break out using this product unless they have a good tolerance for it. This largely depends on a number of skin type factors.
A comedogenic rating of 5 is a high probability of clogging pores and causing break out.
Hair porosity simply refers to your hair's ability to absorb and retain moisture, and here are three ways to determine where yours falls on the porosity spectrum: low, normal or high
Low porosity means the cuticles are very compact and not as susceptible to receiving hydration. Low porosity hair characteristics include dry hair, and in some cases, it’s hard to keep this hair texture wet, because water can bead up and roll right off the strand. Product can also sit on top of strands.
Hair with medium porosity often requires the least amount of maintenance. The cuticle layer is looser, allowing just the right amount of moisture to enter while preventing too much from escaping. Hair with normal porosity tends to hold styles well, and can be permed and colored with predictable results.
High porosity can be either an inherent property of hair or the result of damage from chemical processing, rough treatment or environmental damage. High porosity hair has gaps and holes in the cuticle, which let too much moisture into your hair and leave it prone to frizz and tangling in humid weather.