How long does a perm last on straight hair

I know how to wrap the hair and everything, but the only thing I don't know is how long should I keep on the waving solution and the neutralizer? Thanks!
 
A: Most perm formulas call for the waving lotion to be applied and left on the hair for a maximum of 20 minutes.

After 10 minutes begin checking the curls at random to see if the correct curl amount has formed. Unroll the rod gently and look for an S-shaped wave pattern along the hair.
 
If the S-curl is not there, leave the hair for another 5 minutes and check again.

Once you see the proper S-wave, proceed to the rinse, otherwise, wait until the full 20 minutes have passed and proceed to rinsing. The hair is then rinsed for at least 3 minutes using warm water, and the rods are patted with a clean, dry towel to blot up the excess water.
 
Next, the neutralizer is applied and left to sit for 5 minutes (you likely will not need the entire amount), after which the rods are removed and the remaining neutralizer is appli

how long does a perm stay in

how long do a perm stay in your hair