Pulmonary embolism is the sudden blockage of a major blood vessel (artery) in the lung, usually by a blood clot . In most cases, the clots are small and are not deadly, but they can damage the lung. But if the clot is large and stops blood flow to the lung, it can be deadly.
The term chiaroscuro (from the Italian words chiaro, meaning light, and scuro, meaning dark) refers to the use of light and shade in a work of art to define three-dimensional objects. Masters of this technique were the Italians Leonardo da Vinci and Caravaggio and the Dutch painter Rembrandt.
Chiaroscuro woodcuts began as imitations of this technique. When discussing Italian art, the term sometimes is used to mean painted images in monochrome or two colours, more generally known in English by the French equivalent, grisaille.