Katy asks 'Can you humidity proof your hair?'
I often simplify the structure of hair but it is actually more complex than it seems. It is made up of proteins which will bind small amounts of water in humid conditions (J. Soc. Cosmet Chem, pg 447-470 1972).
I do think that hair responds to humidity in a way that it should. Humidity proofing sounds like asking a teaspoon of sugar not to dissolve in glass of water. Equally the protein in hair takes up water because it is natural for any chemical (including the proteins in hair) to seek to be in the most stable state.
I have previously blogged about mineral oil and coconut oil both having a role in minimizing shrinkage. Oil films can help prevent moisture uptake - Read the article here. Additionally one result does show a depositing conditioner with polyquaternium 70 has antifrizzing properties (J Cosmet Sci, pg 393-404,2007).
I don't really think you should try to humidity proof hair. I think it may be easier to style hair in such a way that humidity does not affect it. Hairstyles that involve a non natural curl (for example twist outs, knot outs, braids outs, rollersets) are begging to be destroyed ( J. Soc. Cosmet Chem, pg 447-470 1972). Hairstyles that are removed from the hair's natural state such as flat ironing and blowouts are equally going to be massacred by humidity.
What styles could work?
1. Fixed styles like braids, twists or cornrows are an obvious choice.
2. Wash and go styles (expect shrinkage) which keep the hair in its natural state
3. Pin up styles and buns which 'hide' the majority of the hair from the water vapour in the air and therefore the style is maintained.
My advice - Take the path of least resistance. Why bother doing all the hard work with styling yet when you go outside, your hair is simply going to revert?
Have you 'humidity proofed' your hair, if so, how?