Also called “green burials,” natural burials reject chemical preservatives, traditional metal coffins or hard-wood caskets (which are typically made from wood harvested in rainforests), and other features of costly modern burials. Going green is a low-cost, highly personal alternative to a conventional burial. Un-embalmed remains are kept cool for viewing, then put directly into the ground, either shrouded in cloth or buried in natural caskets made of biodegradable materials, such as cardboard, wicker and pine. Burial vaults – underground, concrete reinforcement used to ensure that graves do not collapse – are not used.