|Joseph Allen Minturn (c1921), camouflage backdrops|
Surely, these trompe l'oeil backdrops cannot have been used very often because they only work effectively if viewed from front and center.
Below is one of the few photographs of an installed backdrop, but because it was photographed off-center from the right, the illusion that the railroad tracks continue into the distance is simply not convincing.
One that is far more convincing was used for editorial purposes in a newspaper cartoon (c1919) shown below, titled CAMOUFLAGE.
In addition, a few days ago, we ran across a reference to a comparable trick in an unsigned WW1 news article headed WILL YOU TELL ME? in The World's News (Sydney AU), February 9, 1018, p. 20—
…The foremost artists of France are engaged in this magic work [of camouflage], and an American unit of camoufleurs has been organized… One of the most amazing exploits in camouflage was achieved by the French last year. A German position commanded a railway track far into the distance back of the French lines. One night there was set up across a village street that was needed a huge painting of the track, trees, poles, horizon, hills and all. The trains passed safely behind the screen. The enemy never discovered the trick.