What military preservation method is utilized to protect against water vapor?

Method 40 is specifically designed to protect against water vapor. This method involves using materials and techniques that create a barrier against moisture, which can be detrimental to the integrity and longevity of military equipment during storage and transportation. By employing this preservation method, items are able to resist any potential corrosion or degradation caused by environmental moisture.

In contrast, the other preservation methods listed do not focus specifically on water vapor protection. They may target different types of environmental factors or conditions, such as dust or temperature fluctuations, but they do not offer the same level of defense against moisture intrusion as Method 40 does. Understanding the purpose of each method helps ensure that the correct preservation techniques are applied based on the specific risks associated with the materials being stored or transported.