Typically hair elastics with a metal clamp will break and damage hair as the edges of the clamp can break hair when wrapped around.  Rubber will oftentimes snag on hair and create tangles because it rolls in itself, which can cause damage to hair.  All of the hair ties on our list are damage-free options, which is why we consider them the best hair ties for babies.  Cotton and nylon will easily slide off of hair without causing damage, silicone and TPU style bands can be cut when removing to avoid any potential pulling, but will not cause creases or damage to hair when in use.