The basic material is almost always the same, cast iron forms the basis of a weight plate. If you only train on the inside, you can safely choose simple cast iron. Chrome-plated weight plates are chic, but chrome-plating is only really necessary for outdoor training or when storing the weights in the basement or garage. Chrome does not rust. Rubberised weight plates have a better grip and add colour. This is a popular alternative, especially for aerobic weight plates, but also protects the floor at home. Inexpensive alternatives to cast iron can be found in rubberised cement plates, but cement is brittle - cast iron is the more durable choice in any case. Cast iron weight plates are, after all, indestructible.