lol, she will have orange hair!
would you seriously spray a blonde girl with out a cap?
i dont spray anyone with out a cap,
cover yourself, next she will be sending you a hairdressers bill! for turning her blonde hair orange
this is an interesting thread and perhaps it depends on your solution. I use Nouvatan and did Nouvatan training. At the training we were told that you didnt need to wear caps as the solution would just wash out. At the time I had bought 100 disposable caps so I am working my way through them but when i finish, I dont intend to buy anymore. So maybe it depends on solution you use?
As far as I am aware and from experience you do not generally need to have a cap for blonde hair, I have never turned any of my many blondes orange!!!!!!!!
However, I was told that if the hair has just recently been highlighted or similar, then it is a little more porus so there may be a small chance of it absorbing the guide colour.