practice-focused evaluation of paint and coating techniques for dic-based surface deformation measurement on biological skin

This study addresses a key prerequisite for applying digital image correlation (dic) to quantify surface deformations on biological skin: selecting paints and surface preparation techniques that produce reliable speckle patterns. the goal was to identify practical, skin-safe methods that combine high contrast and pattern stability with accessibility for routine experimental use. although the aim is human skin testing, porcine skin was used here as a biological analogue. several coating strategies – including body paints, cosmetic powders, and technical spray coatings – were compared under controlled conditions, with attention to cleaning protocols, storage, and preparation-to-measurement intervals. performance was evaluated in terms of adhesion, durability, contrast quality, and skin compatibility. results showed that technical spray coatings yielded the most stable patterns, while cosmetic-based approaches offered gentler application with acceptable accuracy. validation experiments confirmed that commercially available materials can deliver both precision and safety. the study concludes with practical guidelines for balancing measurement accuracy with ethical and biological considerations, providing researchers with a foundation for reliable dic measurements on living tissue. these findings also highlight the specific challenges of dic measurements on biological skin, particularly paint drying and cracking, accumulation in tissue folds, and the influence of skin freshness on measurement reliability.