EFCO manufactures architectural windows, curtain walls, storefronts, and entry systems designed for commercial construction needs, sold through independent sales representatives across the United States.
Short History of Black Pigments. Carbon black was the first black. This dull black is the easiest to manufacture because it is made of charcoal. Another black is vine black, which is traditionally made by charring desiccated grape vines and stems, which produce beautiful bluish blacks. Bone black, made of burnt bones from prehistoric times, is the deepest available black.
Melanoma (skin cancer) An important cause of black spot on the skin is melanoma, the most dangerous type of skin cancer.It is caused by abnormal changes in the melanocytes, or cells which produce the skin pigment called melanin.