During the mid-20th century there was new utility in combining scientific, artistic, and military knowledge for the development of effective military camouflage. When WWII was declared the military began recruiting seemingly disparate specialists, such as surrealist artists, a zoologist, and a magician to train in concealment: to become camoufleurs. Across diverse environments and battlefields these camoufleurs plied their trade of secrecy, in the process militarising landscapes and their knowledges. This paper will explore how camouflage was developed for different interrelated surfaces during war, whether for the sea in WWI, the earth, or in response to aerial warfare. In particular this paper will explore the surface of sand in the Desert War in WWII, which demanded a new relationship between modern militarism and knowledge of the earth's surface, in order to develop effective camouflage. In turn, it will reveal that camouflage was a defining factor influencing the geographies of the desert as a theatre of war, transforming it into a bewildering topography requiring, as one soldier put it, 'mental guts'.