With modern manufacturing methods, I don't see why they can't move away from bars (that they are drilling out and putting tungsten in) to too thin to add other metals to flats like the size of a shirt pocket fit wrapped in a sealed see-through aluminum coating, providing visual certification of US Mint and a perfect weight that must be verified for legal tender along with sealed in RFID where the reader verified visual serial number with RFID and secret US Mint coding algorithm that is an offset of serial number visual and individual mfg. ID (off a system never accessed to Internet for security reasons)... no more bars, that's old fashion lazy stuff.
And on a side-note while the see-through Al was in a Star Trek movie at a time it wasn't reality, that on radio news over a year ago I'm sure, I heard they figured out how to make clear Aluminum.
