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Why are fingerprints especially noticeable on areas of friction?

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A pangolin walks through grass with a blue circle around it and the word endangered written in white across the image. — Integument The pangolin is the only mammal in the world covered in scales.

Fingerprints are especially noticeable on areas of friction, such as the palms and soles, because these regions are etched with distinct, alternating ridges and grooves known as dermatoglyphics. These ridges have a high relief and follow a consistent structural plan, which makes their patterns more evident than the general skin lines found elsewhere on the body.1

The prominence of these patterns is further enhanced by the presence of sweat glands, which dot the length of each ridge. Because these ridges are anchored to the dermis by a double row of peglike protuberances called papillae, they maintain a stable, unique structure that does not alter with age. This high-relief topography, combined with the secretions from sweat pores, allows these areas to leave clear, identifiable impressions, making them ideal for personal identification.12