Trench art is any decorative item made by soldiers, prisoners of war or civilians where the manufacture is directly linked to armed conflict or consequences. Common articles this includes are decorated shell and bullet casings and items carved from wood and bone. Not limited to the World Wars, the history of trench art span conflicts from the Napoleonic Wars to the present day. Although the practice flourished during World War I, the term 'trench art' is also used to describe souvenirs manufactured by service personnel during World War II. Source: wikipedia (edited).