In 1974, XX kiln for Mao Zedong special & amp; quot; Mao porcelain & amp; quot; & amp; quot; white as jade, bright as a mirror, thin as paper, sound like a thunderbolt & amp; quot; characteristics, known as & amp; ldquo; the glory of the 20th century, the Chinese porcelains & amp; rdquo;, XX kiln is known as & amp; ldquo; xxx& rdquo;.