It would be even better to find tungsten shot to use for slinky's! I find using pencil lead to be a royal pain. It hangs up more often than slinky wieghts and is not nearly as user friendly. I would love to know if there are any studies done on tungsten as far as being good/bad for the environment. I would also love to find a place to purchase bulk tungsten shot/beads in the correct size for slinky wieghts.