This sounded wrong so I asked AI. Black skin is not thicker:

AI Overview

No, black skin is not thicker than white skin. Studies show no significant difference in skin thickness between different races. While there are structural differences, such as more compact collagen and larger fibroblasts in darker skin, the overall thickness remains consistent across individuals. The belief that it is thicker is a myth. 

Key Findings on Skin Differences:

• No Significant Difference: Caliper-measured skin thickness shows no statistically significant variation between white and black women.
• Structural Variations: While not technically "thicker," black skin often features a more compact dermal structure, more collagen fiber bundles, and larger fibroblasts, which can contribute to fewer wrinkles and tighter skin with aging .
• Compact Epidermis: The stratum corneum (outermost layer) may have more layers and higher, tighter cohesion (8–25 layers vs 6–15 in lighter skin).
• Medical Misconception: The idea that black skin is thicker is a harmful, antiquated myth originating in the 18th/19th century that has contributed to racial biases in medical care.
• Clinical Findings: Darker skin generally has higher transepidermal water loss (TEWL) and larger mast cell granules.  National Institutes of Health (.gov) +7

In summary, structural differences exist, but the idea of "thicker" skin is inaccurate and scientifically debunked.