Description
What's the difference between a Hair Bleach Kit volume 40 & a volume 30, & I have dirty blonde hair, which volume should I use?
I plan on bleaching all of my hair by the way, I'm not just doing highlights.

Explanation & Answer

40 volume is stronger and it works faster than the 30 volume, but it also damages hair a lot more easily. if your trying to do highlights I would go with the 30, but if you're doing all over color I would go with the 40..and make sure your hair is a very pale yellow before you wash the bleach out or it will be orange.
or
The developers. 40 volume is a lot stronger, and processes faster then 30. And I wouldn't use 40 volume, unless you have colored Black hair.
