What are rainbow loom bands made of?

Rubber! They're called rubber band bracelets! :) Hope this helps!

The bands sold for use with the Rainbow Loom are made of some type of rubber, however, the exact formula for the bands is copyrighted and not available to the general public. Most of the bands are labeled "latex free," suggesting that they may be safely used by individuals with an allergy to latex. Special edition bands are available that are made of silicon rather than rubber.