Which innovative packaging feature was specifically included in WWII American K-Rations to improve soldier morale?

During World War II, product packaging took on strategic importance as militaries developed combat rations. The American K-Ration was a revolutionary combat food solution that combined nutrition, portability, and surprisingly sophisticated packaging psychology. Beyond merely preserving food, the packaging incorporated design elements specifically crafted to boost troop morale in difficult combat conditions. Test your knowledge about this fascinating intersection of military history and product packaging innovation!

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Patriotic illustrations and messages printed on inner wrappers to be discovered during consumption
Glow-in-the-dark packaging elements for nighttime identification
Edible rice paper wrappers to eliminate waste in combat zones
Temperature-sensitive indicators showing when contents were unsafe to consume