What is typically used in an air tray for burial?

The option that mentions a cardboard covering for the casket is relevant because air trays are typically designed to facilitate the handling and transportation of human remains in a manner that is both practical and respectful. An air tray serves as a framework to support the casket during transit, often containing a cardboard sheet on top to cover the casket. This setup allows for proper ventilation and is generally lightweight and economical, which aligns with the purpose of an air tray as a means for transporting remains without the addition of ornate or heavy materials.

Using a cardboard covering is advantageous because it is cost-effective, easy to handle, and provides a simple yet respectful option for burial or cremation settings. This is especially significant in instances where a straightforward and unembellished approach is taken, such as in direct cremation or more economically conscious burial practices.