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What Is A Soap Cap And Why Should You Use It?

Have you ever heard of the term, “soap cap”?

If you’re into hair color, you need to know what a soap cap is. Let’s talk about how you can use this awesome technique to your advantage.

There are a few different types of soap caps (also known as shampoo caps, or color balancers). In this post, I’ll explain what they are and how to use them.

If you are a DIY hair colorist, you should probably know how to use a soap cap to your advantage. This professional technique is the perfect way to freshen up your hair color, while doing minimal damage do your hair.

What You Need to Get Started:

First things, first… you’re gonna need some supplies. Don’t worry, I got you covered.

  • 20V Creme Developer
  • High-Quality Hair Lightener
  • Clarifying Shampoo That Won’t Dry Out Your Hair
  • Hair Coloring Kit
  • Processing Caps
  • Leftover hair color (depending on the type of soap cap)
  • Gloves
  • An old towel to drape around your neck

I also highly recommend you follow up with a deep conditioning treatment to keep your hair happy. I LOVE the It’s a 10 Miracle Deep Conditioner for projects like this.

1. The “Traditional” Soap Cap with Color

Preparation of hair dye. Isolated on white background

This type of soap cap can be used to refresh dull hair color.

To perform a traditional soap cap: 

  • Mix hair color with equal parts shampoo
  • Apply to the hair and thoroughly saturate
  • Process for 5-10 minutes
  • Rinse, shampoo and style as usual

This method works best if you want to freshen up your color without recoloring your hair.

For example, if you’re just touching up your roots, you can use this method to revive the rest of your hair without the extra damage.

It could also just be used to refresh color between applications. The added shampoo dilutes the color so it won’t darken the previously colored hair.

It also ensures even application, which is a must.

2. Soap Cap with Bleach and Developer

Portrait of beautiful young woman dyeing hairs - isolated on white

I use this soap cap technique reasonably often on my own hair, as it is beneficial for platinum blonde hair. It can also be called a “color balancer” or “bleach bath.”

I use it to freshen up my bleached hair after touching up my roots or even just to freshen up in between applications. It does a lot less damage than re-bleaching the hair over and over again.

You could also use this type of soap cap to lift color gently. For instance, it will take out most semi-permanent colors without doing extensive damage.

You could also try to gently lift darker colors without doing too much damage. The Paul Mitchell color line recommends doing this before any color service (when switching color lines) to create a “fresh canvas” for the new color.

To perform a color balancer, you need to mix equal parts bleach, shampoo, and developer. Like the previous form of soap cap, process for 5-10 minutes, then rinse and deep condition.

3. Soap Cap with Bleach, No Developer

Portrait of young beautiful woman washing her head

I honestly just learned about this type of soap cap yesterday, and it’s pretty much the greatest thing ever. You can mix powdered bleach with shampoo, and it will lift color out of the hair. Skipping on the developer cuts down the damage done to the hair.

Yesterday, my co-worker tried to tone her hair with Redken 8T (Titanium Hair Toner), which is silver for those of you that don’t know. Well…her hair quickly turned silver. We used this method of soap cap to lift the color out of her hair safely.

Scientifically, I am unsure of how the bleach works without peroxide; I think it has to do with the oxygen molecules from the water mixing with the bleach.

Anyways, believe me, it works, and it does very minimal damage.

Now you know…

Hollee Wood Headshot


Hollee is a licensed cosmetologist with over nine years of professional experience in the hair industry. With her unique insight and versatile experience, she’ll help you discover the latest hair trends or even crush your next DIY hair project.

Learn more!

Your Turn:  Did you enjoy this post? I’ll love you forever if you share it with your friends on your favorite social media website…

Have you ever used a soap cap to freshen up your hair color? Do you have any tips to add for other DIY hair colorists? I’d love to hear your feedback in the comments section below…

RELATED: How To Use A Hair Toner For Brassiness

Sheila johnston

Tuesday 11th of October 2022

I have very long damaged medium coppercolored hair and need A gentle way to revive ColOr through thE length Of the hair. I use wella color charm light copper permanEnt color. Is dOing equal Parts color formula and CLARIFYING shampoo the best tecHnique to use?


Monday 12th of September 2022

In the #3 Technique, you mention : "Scientifically, I am unsure of how the bleach works without peroxide; I think it has to do with the oxygen molecules from the water mixing with the bleach." so do you mix the bleach with water and the shampoo or what?? (just a bit of clarification to us who have never tried this thing before) Thank You!


Saturday 6th of August 2022

Just want to confirm the first technique there is NO DEVELOPER, is that correct?


Tuesday 2nd of August 2022

I have medium-dark brown hair and about 50-60% gray. I've been using natural henna. It's supposed to be just ground henna leaves. No other plants. So it's very orange-red. Over time it darkens from repeated applications. I also had my hair lightened with a high lift blonde I did myself loreal high lift for brunettes. They don't make it anymore. So my hair was really bright orange red and I loved it. As time goes on that was cut off and my natural dk brown turns out much darker with the henna now. I tried bleaching a couple years ago and my hair did not lighten very much. Now, I researched and faded my henna a bit with vitamin c powder and with a coconut olive oil mixture. This pulls the henna out. But not completely. I still want my hair lighter so the henna will be really bright. Do you suggest a soapcap with developer or without? Proportions of bleach and shampoo are 1:1? I also tried highlights. Which worked pretty well. By traditional bleach and developer, then HENNAed my whole head. So some of my hair was brighter.

Sheila Johnston

Sunday 30th of January 2022

I have long pOrous hair. Ive been using wella light auburn permanent colOr, but the ends get faded in time. Whats the least damAgIng way To revive the color on the ends? Could I do a soapcap with half condItionEr & color, no developer?