Light skin of UVA can penetrate deeply into the dermis in persons with light skin pigmentation with little protective melanin pigment. The characteristic of fair skin, red hair, and freckling is associated with high amount of pheomelanin, little amounts of eumelanin. This phenotype is caused by a loss-of-function mutation in the melanocortin 1 receptor (MC1R) gene. However, variations in the MC1R gene sequence only have considerable influence on pigmentation in populations where red hair and extremely fair skin is prevalent. The gene variation’s primary effect is to promote eumelanin synthesis at the expense of pheomelanin synthesis, although this contributes to very little
Fugitive pigment for a number of reasons: availability and cost of pigments; being more concerned with the appearance of colors available only with fugitive pigments than with permanence; ignorance regarding the volatility of the pigments; or the desire to have a painting change in appearance over time. Fugitive pigment Fugitive pigments are impermanent pigments that lighten, darken, or otherwise change in appearance or physicality over time when exposed to certain environmental conditions, such as light, temperature, humidity, or pollution. Fugitive pigments are present in types of paint, markers, inks etc., which are used for temporary applications. Fugitive inks which washed away when