When Should I Use 30 Or 20 Volume Developer?
The choice between using 30 or 20 volume developer depends on the desired result. If you want to lighten your hair color significantly, use 30 volume developer. This developer is strong enough to lift 3-4 levels. If you want to darken or deposit color, use 20 volume developer. It is gentler on the hair and helps to deposit color without causing much damage. However, always follow the manufacturer’s instructions and do a patch test on a small section of hair before using any hair dye or developer.