Mylar balloons (also know as foil balloons) look great and last a long time. These balloons are actually made of a very lightweight foil that holds the air or helium (that you provide) inside for a much longer period of time than latex balloons. All mylar balloons are shipped deflated and all you need to do is take them to your local supermarket or superstore and have them fill it for a nominal cost. You may even be able to purchase a small disposable helium tank at a superstore or rent a tank from a rental company. That will enable you to fill up your mylar balloons at home.