Without color; lacking characteristics which give variety. blank (Adjective). Free from writing, printing, or marks; having an empty space to be filled in; as, blank paper; a blank check; a blank ballot. blank (Adjective). Without expression.
Yes they do damage hair. Every time I have tried one ,I wound up looking like a Q-tip or my head looked like cotton. A perm will damage even more and look worse if you have been coloring your hair. There's chance of it looking okay if you don't color your hair.
It is also more damaging to the hair. The thio-free perm has less of an odor, and causes less damage. It also produces a looser wave, and does not last as long as a traditional perm. The digital perm lasts 3-6 months, and can recondition the hair, making it smoother after treatment. It produces a looser wave than the tight curls of a traditional perm. This perm can also damage hair, but is not as immediately damaging as a traditional one. Perms can take up to 3 hours to be completed, but the result creates long-lasting waves that are even visible when the hair is wet.