In about the 9th century, Chinese artisans abandoned the Han blue colour they had used for centuries, and began to use cobalt blue, made with cobalt salts of alumina, to manufacture fine blue and white porcelain, The plates and vases were shaped, dried, the paint applied with a brush, covered http://felixohasj.designertoblog.com/25205779/indicadores-sobre-blue-light-que-debe-saber