How Long Should You Leave Wella T18 Toner in Your Hair? How should you use it?

woman with watch on her hand to control time of T18

Leave Wella T18 toner in your hair for 20 to 30 minutes.
Since Wella T18 is used to tone bleached hair that has reached a light blonde 9 or extra light blonde 10, you must NEVER leave it on your hair for more than 30 minutes.
Otherwise, you could injure your scalp and irreversibly damage your hair.
That's why you leave Wella T18 on for at least 20 minutes and at most 30 minutes.

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How to use Wella T18 toner with a 20-volume developer

I think you now know three fundamental things about Wella T18 toner:

Don't leave it on your hair for less than 20 minutes or more than 30 minutes. We'll go into more detail on this later.
You use it after bleaching or using blonde dyes to tone extra light hair and leave it ashy-colored.
It doesn't work on hair colors such as brown 4 or light brown 5.

Is your hair very light blonde? Then let's see why you should respect the exposure time for Wella T18 to the letter.

Why you should leave Wella T18 toner on your hair for 20-30 minutes

T18 Wella hair toner

Although the manufacturer states that you should leave T18 in the hair for 30 minutes, you can always rinse it out after 20 minutes if you've got to the color you want. That said, you must leave it on for at least 20 minutes.

Why? Because if you're already at a high blonde color number, your hair has likely been bleached several times. It will therefore absorb any product you apply more quickly.

For example, with one of my clients, Maria, we planned to bleach her dark brown hair over several sessions to get to a very light blonde shade.

After several months, when we finally reached the extra light blonde color 10, we had to start using the toner to leave it ashy-colored, without harsh colors.

Maria asked me to use Wella T18 to tone her hair, and I agreed. Before applying it to her hair, I already knew that although the manufacturer recommended leaving the toner in the hair for 30 minutes, in Maria's case, I would probably rinse it out after twenty minutes.

Why? Because since her hair had gone through several bleachings, it was very porous. So it would quickly absorb the toner. And so it did. After 22 minutes by the clock, I rinsed out the toner. The result was spectacular. Her hair was perfect ash blonde.

You must not go over this time. If your hair is toned before thirty minutes is up , rinse the toner out. It's not necessary to over-process your hair. You may even feel a burning sensation on your scalp if you leave it on for longer.

And you shouldn't rinse it out before 20 minutes either . Wella T18 is a homemade toner. So if you remove it before 20 minutes, your hair won't be ashy-colored.

How to apply Wella T18 toner correctly

hair before and after using T18r

To apply Wella T18 to your hair, you will need:

Wella Color Charm T18 toner
20-volume developer, or 10-volume if you have very light hair
Gloves
Brush
Plastic bag

Application:

Put on your gloves and prepare the mixture of toner and developer in the plastic bag. Stick to the right proportions.
Comb through your dry or damp hair, dividing it into several sections to make it easier to distribute the toner.
Start applying the toner from the roots to the ends, covering every part of your hair.
When you're finished, cover your hair with a shower cap. Leave the toner on for 20 to 30 minutes , checking the color every five minutes.
After that time, rinse it out with lukewarm, almost cold water, letting it run through until it's completely clear.
Don't use shampoo. Apply conditioner to the mid-lengths and ends only and rinse.
Drain excess water with a towel and dry your hair naturally.