What effect does heat have on fabric before its application?

Heat has a beneficial effect on fabric before its application, as it helps relax the fabric, making it easier to work with during the covering process. When fabric is subjected to heat, the fibers can become more pliable. This pliability allows for better manipulation of the fabric, facilitating smoother application and conforming to the contours of the aircraft structure. By relaxing the fabric, it reduces the risk of wrinkles or tension that could impair the final finish.

The option that mentions damage or reinforcement does not accurately reflect the intended purpose of heating fabric prior to application. Additionally, while heat does not inherently change the weight of the fabric, it primarily serves to enhance handling characteristics, which is crucial for achieving a professional-grade finish in aircraft fabric covering.