A product's cosmetic elegance is the sum of how it feels, how it sits, and how it looks on the skin. Aelon IQ characterises four aspects of cosmetic elegance: the tactile residue a product leaves, its structural weight, its optical finish, and, for mineral sunscreens, its potential to leave a white cast. These properties are distinct from a product's functional performance, but they are not always separable from it: some are matters of aesthetic preference with no correct answer (for example, the optical finish); others can limit real-world use and are therefore treated as bearing on a product's practical value (Oliveira, R. and Almeida, I.F., 2023; Addor, F.A.S., et al., 2022).

 

What Aelon IQ analyses 

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Tactile residue
 

After a product absorbs, any remaining surface film produces one of two forms of residue, which may occur separately or together. A sticky or tacky feel arises principally from humectants, the water-binding ingredients such as glycerin and other polyols, that at sufficient concentration may leave a tacky surface film. A greasy or oily feel arises from oily material that does not absorb: heavier oils, butters, waxes, non-volatile silicones, and occlusives, but also lighter carrier and/or solvent esters at high concentration.

 

Across the dermatological literature, greasiness and stickiness are among the attributes most consistently associated with reduced cosmetic acceptability and lower adherence (Eastman, W.J., et al., 2014). However, the functional significance of a greasy feel is variable. In a moisturiser the responsible material may be an occlusive which helps reduce transepidermal water loss (TEWL) but is also greasy and heavy, so the feel coincides with a functional component. In other cases, the same feel derives from lighter esters or silicones that provide slip and/or solvency without significant occlusion. A greasy feel therefore does not by itself establish moisturising capacity: it registers unabsorbed oily residue, but not whether that residue reduces TEWL, as heavier emollients and occlusives do (Lee, C., et al., 2019).

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Structural weight

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​This dimension reflects how substantial a formulation is on application – from weightless to heavy. Weightless textures are watery, fluid formulations with essentially no lipid content, applying almost like water. Light textures are fluid or gel-like, spreading and absorbing readily without structural substance. However, a weightless or light application does not ensure a clean after-feel – a fluid may spread lightly yet leave a tacky or oily film once settled. 

 

Heavy textures are rich, thick, or cushiony formulations that apply as a substantial layer and are associated with greasy tactile residue. However, as previously noted, neither the greasy residue nor the associated heavy texture ensure hydration and/or TEWL reduction. In some well-formulated products designed to prevent water loss there may be a correlation between the product’s overall moisturisation potential and its residue and structural weight, whereas in other products the heavy texture and greasy residue may be due to a high load of emollient esters that provide slip or are used as carriers or solvents for other ingredients without providing lasting moisturisation. Real moisturisation needs humectants to bind water, richer conditioning emollients and occlusives, and skin-identical barrier lipids (ceramides, cholesterol, free fatty acids).

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Optical finish

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Optical finish – whether the skin appears matte, dewy, or natural after product application – is primarily an aesthetic property. A matte finish typically results from a substantial load of light-scattering or oil-absorbing powders. A dewy, luminous sheen results mainly from oils and humectants that leave a reflective film, and secondarily from pearlescent pigments such as mica. A natural, skin-like finish falls between the two, neither mattifying nor visibly reflective.

 

Because the oils and humectants that produce a dewy, luminous sheen are largely the same materials that may leave greasy or tacky residue (with the exception of pearlescent pigments), finish tends to move with those dimensions. However, a dewy, luminous finish is sought by some for the appearance of radiance and so-called ‘glass skin’ even if that feature comes with an unwanted residue. 

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White cast

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This dimension applies only to sunscreens formulated with mineral (inorganic) UV filters, zinc oxide and titanium dioxide, which can leave a visible white or chalky residue that chemical (organic) filters do not.

Formulations address white cast in various ways. Tinting colorants counteract the whiteness across a range of skin tones and are the more effective approach, working largely independently of how much mineral filter is present. Using particle coating and dispersing agents, which reduce clumping and improve how the mineral particles lie on the skin, is a meaningful strategy at low to moderate mineral loads but less reliable at high loads and on deeper skin tones. Reducing mineral particle size to microfine or nano grades also lowers visible-light scattering and increases transparency, but on its own does not eliminate white cast – other strategies are still required. Because white cast affects whether a mineral sunscreen is worn, it is treated as a performance factor rather than a matter of preference, as the optical finish is. 

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Summary

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Tactile residue, structural weight, and, for mineral sunscreens, white cast are properties capable of limiting real-world use and are, therefore, treated as bearing on a product's value. Optical finish is a neutral aesthetic preference and is described without being scored. All of these properties characterise the sensory and visual experience of a product, which the reader may weigh against personal preference and intended use.

 

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References 

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Addor, F.A.S., Barcaui, C.B., Gomes, E.E., Lupi, O., Marçon, C.R. and Miot, H.A. (2022) 'Sunscreen lotions in the dermatological prescription: review of concepts and controversies', Anais Brasileiros de Dermatologia, 97(2), pp. 204–222. 

 

Eastman, W.J., Malahias, S., Delconte, J. and DiBenedetti, D. (2014) 'Assessing attributes of topical vehicles for the treatment of acne, atopic dermatitis, and plaque psoriasis', Cutis, 94(1), pp. 46–53.

 

Lee, C., Bajor, J., Moaddel, T., Subramanian, V., Lee, J.-M., Marrero, D., Rocha, S. and Tharp, M.D. (2019) 'Principles of moisturizer product design', Journal of Drugs in Dermatology, 18(1 Suppl), pp. s89–s95.

 

Oliveira, R. and Almeida, I.F. (2023) 'Patient-Centric Design of Topical Dermatological Medicines', Pharmaceuticals, 16(4), 617.