Comparison of melanin granules in darkly pigmented (left side) vs. lightly pigmented (right side) epidermis. Both skin types have the same endowment of pigment cells or melanocytes. But, the pigment granules produced by melanocytes in dark skin are larger and more numerous than those in light skin. When transferred to cells of the epidermis (keratinocytes), pigment granules in dark skin (left side) persist as the cells move towards the skin surface and some of the granules “escape” into the spaces outside the cells. In contrast in lighter skin (right side) the small granules tend to cluster over the top of the nucleus (‘nuclear cap’) where they can protect the DNA from sun damage. Very few make it into the outer skin cell layers and few of those are found outside the cells there. Drawing by Jessica Kraft.