The difference is the strength of the developers.
A 30% developer will help you achieve a minimal lift and a 40% will make the color brighter/louder which will result in a maximum lift.
In other words a 30 would lift your hair 3 times and a 40 will lift it 4X times the color. When coloring your hair like this it goes through stages of lightening that's why stylist put it on & check back to see if the color has made it to the desired color that you want or they want to achieve for you.
creme developer is thicker and more conditioning Also.......Clear developer is mainly used when coloring out of a bottle and cream is used when coloring with a bowl & brush.
30 Volume Cream Developer is generally used for high-lift color, blonding, and bleaching.
It won't make it 30. The way developer works is 10 is no lift deposit only and makes hair semi permanent. 20 is 7-10 shades of lift with deposit and makes hair colour permanent. You have to buy 30 volume developer from a sallys beauty supply but 30 is very dangerous for the hair it can damage it severly I recommend sticking to just 20 volume
Mixing 10 volume cream developer with 40 volume cream developer could result in an unpredictable reaction, potentially altering the intended chemical properties of the developer. This could affect the color result and the effectiveness of the hair color product. It is best to use the developer recommended by the hair color product manufacturer for optimal results.
To make a 40-volume developer, you would mix equal parts of 20-volume (6%) hydrogen peroxide cream developer with another equal part of 20-volume (6%) hydrogen peroxide cream developer. This will give you a total volume of 40 (12%).
Mixing 10 Volume developer and 40 volume developer will never make a 20 volume regardless of how much is mixed. In order to make a 20 volume, equal parts of 10 and 30 volumes will need to be mixed. Mixing 10 and 40 will make 30 volume.
2.6 oz of developer.
30 vol is stronger
Equal parts of 10 & 30 V. developer will yield 20 v.
Equal parts of 10 & 30 V. developer will yield 20 v.
It is not recommended to double the volume of developer to achieve the desired strength. Using a 10-volume developer when a 20-volume developer is needed can result in uneven hair color or ineffective processing. It is best to use the correct developer volume for the hair color you are using.
Which developer you use will depend on the color you want to achieve. A 20 developer will give you a darker color than a 30 or 40 developer.