a container for a stack of coins is formed from a length of flexible plastic lay - flat tubing . the container has the form of a hollow cylinder that is open at both ends . the coins are prevented from falling out of the retainer by toggle retainers formed at both ends of the tube by cutting and scoring or perforating operations performed on the container while it is in the flattened condition . these operations can conveniently be carried out on a flexographic converting system . the toggle retainers can readily be opened for removal of the coins , after which the flexibility of the walls of the container permit it to be flattened , thereby saving space during transport and storage of the empty containers . this encourages reuse , which makes the container attractive from the standpoint of both economics and ecology .