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August Soap Challenge Club: Layers with Drop Swirls

The goal

Regular category: using the cold-process soap making technique, create a (minimum) 4 layer soap with drop swirls at the top.


I did the normal measuring and prep with 0.5% Sodium lactate 60% from Wholesale Supplies Plus (WSP) to aid with removal from the mold. I hand stirred the oils and lye water for each color. I mixed each layer's color separately just before pouring, and added some fragrance at light trace to ensure I had plenty of time for the design. Temps were 78/83 F lye/oils.

Using my paint design, I measured each layer as a percent (this did take too long), but I managed to closely replicate my intended design. Each color was effectively a triangle, so then I could calculate the percentage of batter for each color and then get the number in grams.

Check out this soap batter math! Some colors were changed (Brilliant Blue instead of Blue Vibrance, and I didn't have Celestial Silver).

Notebook paper with calculations of soap batter portions using math

Recipe & Process

  • 40% Olive Oil
  • 25% Coconut Oil
  • 20% Palm Oil
  • 10% Sweet Almond Oil
  • 5% Castor Oil
  • 5% Superfat
  • 33% Lye Strength

  • Colors: Mostly from Nurture Soap, TD and Celestial Blue from WSP

    Design: Slanted layers in ROYGBIV (Rainbow!) with a blue sky layer and drop swirls to resemble white / silver / light blue raindrops (and hopefully clouds on top); fragrance Abalone & Sea from WSP.

    For the rainbow, I had my tall & skinny 2 lb mold tilted until I knew the sky over the red was safe (not moving). Then I stood the mold upright. The total batch weight was just over 55 fl oz. before adding additional water.

    I added some distilled water (34g) to the sky and drop swirl layers for a more fluid trace. I also increased each drop swirl to about 100g instead of 87g, but 120-150g probably would have been ideal. All of the batter was used from one large mixing, no waiting hours for any part of this soap (layers up to the clouds on top).

    Behold! My super-impressive Paint design:

    Glorious Rainbow Paint rendering


    • Pour at medium trace, except perhaps drop swirl light-medium
    • Use the wall pour technique to reduce the impact on settling layers
    • I'd try to leave more drop swirl batter, 20% for 3 colors was not enough. I'd take some of the sky's 40%
    • For my second ever drop-swirl, this was still a bit too thick of trace to make intricate swirls
    • Light silver coloring is tough to create in soap, and the blues tend to look more green while mixing than in the final product
    • Making a larger batch to slow the trace plus leaving it mainly uncolored and scented kept it very fluid to use while the layers were setting
    • My layers should have been across the entire bottom of the soap (oops, I didn't see that until too late)
    • Having both my camera's battery run out, and then memory become full while trying to make soap is a whole 'nother layer of frustrating ;)

    From One End of the Rainbow to Another

      Rainbow layer drop swirl Artisan Soap


        • This was such a joy to gift to a friend who has two young daughters. They all loved the bright colors, the smell, and the design! So fun!

          Christa Nova
        • I love your thorough write-up about your beautiful soap! It turned out amazing!! Truly beautiful rainbow with sky and clouds. Just to clarify, there was no minimum number of layers, and the layers just needed to go the length of the mold, not necessarily cover the bottom, so you did great!! It’s a very impressive design for a beginner – you should be very proud!

          Amy Warden

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