Acid Mantle

The acid mantle is a thin, mildly acidic film on the skin surface created by sebum, sweat, and cellular by-products. It supports barrier enzymes and discourages opportunistic microbes.

Why it matters: repeated high-pH cleansing or detergents can slow barrier recovery and increase sensitivity.

Common signs it’s stressed: tightness after cleansing, stinging, “reactive” feeling skin.

How Baseline recipes support it: lipid-based cleansing reduces large pH swings and avoids repeated stripping.

Relevant recipes: Gentle Barrier Oil Cleanse, Protective Touch Balm.

Carrier Oils

Carrier oils are plant oils used as the “base” of a formula. They dilute and carry other lipid-soluble ingredients and strongly shape the feel and comedogenic behaviour of a blend.

Why it matters: the carrier determines slip, absorption speed, and the fatty-acid profile your skin is exposed to most.

How Baseline uses them: simple, few-ingredient blends so you can predict how your skin responds.

Examples on this site: Argan Oil, Olive Oil, Jojoba Oil (where listed).

Comedogenic Rating

Comedogenicity is an imperfect guide to how likely an ingredient is to contribute to clogged pores for some people. Ratings are usually presented on a 0–5 scale (lower = less likely).

How to use this rating:

• Use it as a signal, not a rule: skin type, formula, and percentage matter as much as the ingredient.
• Blend context matters: a “higher” oil used at a small % inside a balm may behave differently than the same oil used undiluted.
• Prefer stability over perfection: if you’re acne-prone, start with lower-rated oils and change one variable at a time.
• Texture notes need context: descriptions like “heavier feel” refer to higher-% or undiluted use; in blends they often feel lighter.

Where it matters here: the recipes are designed to be simple enough that you can adjust carriers if you notice congestion.

Relevant recipes: Nurturing Glow Butter, Protective Touch Balm.

Essential Oils

Essential oils are concentrated aromatic extracts. They can smell pleasant, but they are also common sensitisation triggers, especially on compromised barriers.

Why it matters: “natural” does not mean low-risk; repeated exposure can raise irritation or sensitisation over time.

How Baseline treats them: generally avoided in baseline mode to keep variables and irritant load low. If used at all, it should be rare, very low %, and not on reactive skin.

Relevant recipes: baseline recipes prioritise carrier oils/butters instead of fragrance actives.

Inflammatory Threshold

Skin has a tolerance limit for stimulation. Repeated “small” irritation can accumulate until the threshold is crossed and reactions become frequent and unpredictable.

Why it matters: active-heavy routines can feel fine for months, then suddenly become intolerable.

Common signs it’s stressed: random flushing, stinging from basic products, rebound oiliness or dryness.

How Baseline recipes support it: fewer variables, minimal actives, and consistent textures reduce cumulative load.

Relevant recipes: Gentle Barrier Oil Cleanse, Hydrating Conductive Mist.

Linoleic vs Oleic Balance

Carrier oils vary by fatty-acid profile. Broadly: linoleic-rich oils tend to feel lighter and may suit congestion-prone skin; oleic-rich oils tend to feel richer and more occlusive.

Why it matters: the “wrong” carrier for your skin can feel greasy or contribute to congestion — especially at high % or when used alone.

How Baseline uses this: blends are kept simple so you can swap a carrier (linoleic-leaning vs oleic-leaning) without rebuilding the whole recipe.

Relevant recipes: Nurturing Glow Butter, Protective Touch Balm.

Natural Moisturising Factor (NMF)

NMF is a mixture of amino acids, salts, sugars, and other small molecules inside the stratum corneum that bind water and keep skin flexible.

Why it matters: low humidity and over-washing reduce NMF, leading to persistent dryness even with “moisturiser”.

How Baseline recipes support it: reduced cleansing frequency and sealing on slightly damp skin helps retain existing water and NMF.

Relevant recipes: Hydrating Conductive Mist, Protective Touch Balm.

Skin Microbiome

The skin microbiome is an ecosystem of microbes that can support immune signalling and compete with pathogens on healthy skin.

Why it matters: over-cleansing and frequent “sterilising” products can destabilise balance and keep irritation cycling.

How Baseline recipes support it: gentle cleansing and consistent products reduce disruptive swings in environment and exposure.

Relevant recipes: Gentle Barrier Oil Cleanse, Calming Shave Gel.

Stratum Corneum

The stratum corneum is the outermost barrier layer — a “brick and mortar” structure of corneocytes and lipids. It is the primary physical barrier to the environment.

Why it matters: disruption increases roughness, flaking, sensitivity, and TEWL.

How Baseline recipes support it: butters and balms reinforce lipid continuity instead of repeatedly dissolving it.

Relevant recipes: Nurturing Glow Butter, Protective Touch Balm.

Transepidermal Water Loss (TEWL)

TEWL is passive water loss through the skin. Higher TEWL usually means the barrier is compromised.

Why it matters: elevated TEWL can feel like “dryness that won’t moisturise”.

How Baseline recipes support it: occlusive lipids and timely application reduce unnecessary evaporation.

Relevant recipes: Protective Touch Balm, Nurturing Glow Butter.