Exhibition "Black Out: Silhouettes Then and Now" held in Washington

A man visits the exhibition "Black Out: Silhouettes Then and Now" at National Portrait Gallery in Washington D.C., the United States, on July 13, 2018. The exhibition explores the relatively unstudied art form silhouettes, or cut paper profiles, a hugely popular and democratic form of portraiture in the 19th century, by examining its rich historical roots and considering its forceful contemporary presence. (Xinhua/Liu Jie)