What is this close-up picture? (WotsThat: Thumbprint texture (macro))

Question

What object is shown in this zoomed-in close-up photo?

MagpieKing · Accepted Answer

Thumbprint texture (macro). Thumbprints are often used as a primary identifier in fingerprint databases because the thumb tends to leave the clearest, most complete print of any finger when pressed down naturally.

Answer: Thumbprint texture (macro)

More human close-ups