How was camouflage used to protect gun positions and troop movements in World War I?

During World War I, the emergence of air warfare and the use of military aircraft for aerial reconnaissance necessitated the development of formal camouflage services to protect ground positions and troop movements.1

Because aerial observation allowed the enemy to direct artillery fire and anticipate offensives, major armies organized specially trained troops to practice the art of concealment and visual deception. While specific techniques for gun positions and troop movements evolved significantly by World War II, the foundational practice in World War I involved passive defensive measures designed to defeat enemy observation by disguising installations and activities to prevent them from being identified or targeted.1

Additionally, dazzle camouflage was deployed on thousands of British and American ships during the war. Unlike traditional concealment, this method used bold, geometric patterns to create optical illusions, making it difficult for enemy U-boat gunners to accurately determine a vessel's size, speed, and direction, thereby complicating their ability to aim torpedoes effectively.2