Postcards were a popular means of communication during World War I and the postcard industry at that time employed large numbers of cartoonists and photographers. These cards were exchanged by soldiers and loved ones at home and sought after by postcard collectors who tried to find complete sets of them. Combatants in the war also used postcards for propaganda purposes, especially to encourage support from citizens of neutral countries. Such cards extolled the virtues of each country's military and home front war efforts, presented training and battlefield experiences in positive ways, and mocked their enemies.