Mixing hair dye with an oxidizer is an important part of the hair coloring process. The oxidant is used to activate the dye and ensure a longer-lasting coloring in the depth of the hair.
The ratio of hair dye to oxidizer can vary depending on the brand and type of product. Usually, the ratio is 1:1, which means that equal amounts of hair dye and oxidizer are used. With some hair dyes, it is possible to have a ratio of 1:1/5, which means that one part of dye is added to one and a half parts of oxidizer.
For lighter tones a higher percentage of oxidant is used (12%, 9% or 40 vol, 30 vol), but a lower percentage can be used, while for darker tones a low percentage of oxidant is used (6 %, 9% or 20 vol, 30 vol), but a higher percentage can be used. There are also some hair dye products that have special instructions for mixing the dye and oxidizer that must be followed to get the best results. For example, highly lightening hair dye can be mixed with oxidizer 1:2, or one part dye with two parts oxidizer. For drier and/or treated hair, you can increase the amount of oxidant by up to 15%.
Before mixing the hair dye with the oxidizer in a non-metallic container, it is important to read the instructions on the package and follow the recommendations for mixing and proportioning the products. Also, it is always a good idea to do a sensitivity test before using the hair dye product.
If you want to learn more about mixing hair dye with oxidant and their properties, you can do so here: