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Colour scale: the ultimate guide to colouring glycerin soap

Colour scale: the ultime guide to colouring glycerin soap

It’s a question we’ve often been asked: how much liquid colorant should you add to glycerin soap? The answer depends on the effect you’re looking for, and to save you time and trouble, we’ve done the testing for you!

Glycerin is a popular choice for soap makers because it’s fast, easy, and ready to use immediately! But it can happen to the best of us: we have visions of the perfect outcome dancing in our heads, but the reality doesn’t quite meet our expectations. Below, we’ll give you some tips on how to get as close as possible to the colour you are dreaming of.

Do you measure drops or grams?

First of all, the liquid colorants we sell at Coop Coco don’t all have the same density; in other words, 10 drops of one colour won’t necessarily weigh the same as 10 drops of another colour. For this reason, we decided to base our colour scale on the number of drops per 100 g. of soap. Since the colorants are sold in dropper bottles, it’s easy to compare the colour intensities achieved by adding more or fewer drops.

When testing a new recipe, you can just follow our directions (number of drops per 100 g. of soap) to obtain the desired colour intensity. If you’re planning to remake the recipe, just weigh the number of drops used, knowing this weight will change from one colour to another. So it will be faster next time (easier to weigh 3 grams than to count 100 drops!)

Here are the results of our tests along with our recommendations.

Drum roll please!

We decided to rank the various concentrations on a colour intensity scale of 1-7, with 1 being the lowest and 7 being the highest. Here are the number of drops per 100 g. of soap for each level of this intensity scale.

Intensity Colour Number of drops of colorant per 100 g. of soap
1 Hint 8
2 Pastel 18
3 Light 30
4 Medium 50
5 Pronounced 90
6 Dark 120
7 Very dark 180

Colour scale for transparent soap

Your results will vary depending on the type of glycerin soap you use. Transparent soap (with aloe) requires less colorant to achieve a beautiful effect. Beyond a certain limit, the transparency of the soap seems to decrease.

Even at level 1 (just 8 drops per 100 g. of soap), you can achieve a lovely delicate hue. To achieve an intense colour without affecting the transparency of the soap, we suggest you stop at level 3 (30 drops per 100 g. of soap).
Of course, it all depends on the look you’re going for.

transparent soap

Colour scale for opaque soap

The following are our results for opaque glycerin soaps (white or shea butter). Level 1 gives you a palette of fairly light pastel colours. Levels 4 and 5 start giving you stronger medium colours. You’ll notice that some colours, such as yellow, change very little from one level to another, while others, such as red, change quite dramatically.

We hope this chart will inspire you to have some fun making your next works of art!


What now?

You can now give free rein to your imagination, confident you’ll get the look you want.

And if you’d like to add a splash of colour to your bathroom, take a look at our rainbow glycerin soap.


  • Barbara

    I think I bought the wrong colouring for my bath bombs. I bought ultramarine blue and red and yellow oxides. What can I colour the bath bombs with aND secondly, what can I use the colourings I ordered for? Glycerin soap?

    • Coop Coco

      Hello Barbara,

      First, and this is really relevant: do not use Ultramarines in your bath bombes recipes!! These colourants react with citric acid, releasing hydrogen sulfide and a pungent rotten egg odour… Our colleagues still haven’t forgotten that smell; so please, spare yourselves and skip this mix!!
      To colour your bath bomb, you can use oxides, clay, liquid colourants (for glycerine soap) or even micas.
      You can use your oxides and ultramarine in glycerine soap or cold process soap.
      Have a nice day!

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