Artificial hair integrations is a type of synthetic fiber that can withstand heat up to 400 °F (200 °C), and can actually outlast human hair. It is very similar to human hair given it is tangle-free and has a natural sheen. It can be straightened or curled, however, it takes longer to set and futura cannot be colored. It is sometimes sold as a human hair blend. The human hair shaft is made up of dead, hard protein, called keratin, in three layers. The inner layer is called the medulla and may not be present. The next layer is the cortex and the
Human hair color can be found spread around most of Europe. Studies in 2012 showed that naturally blond hair of Melanesians is caused by a recessive mutation in tyrosinase-related protein 1 (TYRP1). In the Solomon Islands, 26% of the population carry the gene; however, it is absent outside of Oceania. Black hair is the darkest hair color. It has large amounts of eumelanin and is more dense than other hair colors. Auburn hair ranges along a spectrum of light to dark red-brown shades. The chemicals which cause auburn hair are eumelanin (brown) and pheomelanin (red), with a higher proportion of red-causing pheomelanin than