We started our investigation by tuning pre-existing molecular model strategies in order to achieve a further degree of refinement in the understanding of the surface interactions between a hair's surface and external formulations. The separation distance of 18-MEA has an overall impact not just on surface density, but also the barrier properties of the hair surface. Therefore, predicting it accurately is paramount for a good hair surface model. Previously, Natarajan and Robbins' hair fiber surface model was the only available model that incorporated a protein layer . This model was originally built using the full length sequence of KAP5-1 and a canonical β-sheet structural model superimposed on a poly-beta sheet template in which each β-sheet turn on the surface contained a single cysteine residue. This allowed for an inter-attachment distance of 9 Å and an inter-sheet distance of 7 Å, resulting in an approximate spacing of 9.36 Å in a psuedo-hexagonal array. This fatty acid-protein matrix configuration was previously proposed by Negri et al., which incorporated information from multiple studies . Natarajan and Robbins' model was able to reproduce the experimental layer's thickness and estimated 18-MEA distribution and predicted a 9.36 Å separation distance for these bonded fatty acids.. Subsequent modeling studies using a simplified graphene substrate with 18-MEA positioned in a hexagonal arrangement have identified characteristics of hair surface architecture . In these complementary all atom and coarse grained simulations, an optimal grafting distance of 4.9 to 6.5 Å was determined. This observation was corroborated by previous TEM experiments of virgin hair . Additionally, atomic force microscopy studies measured the surface density of cysteic acid, generated by bleaching hair fibers and subsequent cleavage of cysteine-18-MEA thioester bonds, allowing to derive a 6.0 Å mean 18-MEA molecular separation distance . The discrepancy between the two models and experimental measurements led us to propose a hair surface model combining the advantages of Natarajan and Robbins' model while able to accurately represent the 18-MEA grafting distance.