Marking newly hatched chicks

[fresheggs4u]

I have some Black Copper Marans currently hatching from a breeder. I also have some that hatched last week from a different breeder. I would like to mark them and brood them together. It has been suggested that I use small rubber bands to do so. Where in the world do I find rubber bands that small? Someone else suggested using zippie ties. I like the rubber band idea better. Anyone have any suggestions?

Thanks!