Metal Magic Silver Clay is 80% fine silver and 20% binder by weight. It shrinks 25% during firing in comparison to other brands of .999 silver clay that shrink 10 – 15%. Metal Magic Silver Clay is available in 3 three sizes (25, 50 and 100 Gram packs), comes in lump form only, and is priced LOWER than other silver clays on the market. This product is the only silver clay that is available in a 100-gram package.