Bleaching fine hair

[Emmamc]

Hi am at college going into my 3rd year i have a client that would like her hair bleached ( Balayage ) her hair is really fine. Am a bit worried it might just all snap off. She has a brown box dye on it just now. Will it be OK if I use 20 vol and keep checking on it ??

 

[AcidPerm]

Bear in mind that if she's re-applied the box dye, it could be quite fragile especially as it's quite thin to start off with and that might preclude using bleach on it.
If possible, see if you can take some small test cuttings to try out your bleach mix. It will give you a good indication of how the hair will perform and you can show the results to your client if you're at all concerned.