Only those caskets are air (and water) tight which are "sealer" caskets, meaning that they are provided with a rubber like sealing gasket between the lid and the base of the caskets. Usually only metal caskets can be sealer caskets.

"Glass sealer" caskets (protective caskets with an inner glass lid) are an older type of "sealer caskets" (caskets providing an air and watertight seal). Later (for example in the Gulf War) the remains of soldiers were shipped back in glassless "gasket sealer" caskets.

One can find caskets for sale at mortuaries and funeral supply stores, for example Costco. Caskets are also for sale at Sears, Walmart, and Caskets By Design.

Only those caskets are air (and water) tight which are "sealer" caskets, meaning that they are provided with a rubber like sealing gasket between the lid and the base of the caskets. Usually only metal caskets can be sealer caskets.

There are three caskets in The Merchant of Venice. One is made of gold, the second silver, and the last lead.