What is one general purpose of mastic?

Mastic serves the important function of finishing over irregular shapes. Its thick consistency and adhesive properties allow it to effectively cover and seal joints, seams, and other irregular surfaces where insulation is applied. This provides a smoother and more continuous surface, which helps to maintain the integrity of the insulation and can enhance overall performance. Additionally, mastic can provide a weather-resistant layer, protecting the insulation materials from moisture and environmental elements.

While other options mention color, thickness, or electrical insulation, these aspects are not the primary purposes of mastic in insulation applications. Mastic is specifically designed to address the need for a flexible and durable covering that can conform to various shapes and surfaces, making it essential in the insulation process.