For the repatriation of remains, there are rules and regulations concerning the Caskets and Coffins used.
To comply with the Airline regulations the coffins must be zinc lined and there are number of ways to follow for the body repatriation.
Wooden coffins need to have zinc linings. This means the coffin must have an inner zinc to meet the requirements for the Human remains repatriation.
If the coffin is to be used for the funeral overseas a zinc cad-seal can be used and when the coffin reaches the destination country the funeral director can remove the cad-seal and use the coffin for the funeral.
Metal caskets are usually hermetically sealed, and so they will not need to be zinc lined.