used to:

- determine how the hair will react to the color formula

- how long the hair will take to process

- determine how hair will lighten when using enlightener

- assess possible damage, discoloration and breakage

- what strength or volume of developer needed

- if the hair will need to be toned after lightening

strand test

- apply formula that you are using to a small hidden piece of hair (usually within the back, bottom section)

- allow to sit for recommended processing time

- remove product and assess hair