Dual soap mold

As a way to illustrate the process of dual molding soap, I cast a logo (with permission) into a bar of soap. The first run didn’t work out, but I included it anyway, truncated, because it still shows a good process of making a one-off mold. My carving just didn’t work out.

The final bar was a made by designing the bar of soap in Solidworks, 3D printing it, casting the mold in silicone, then finally pouring soap batter in to solidify. (This was all my lovely wife's idea.)

The charcoal dye worked OK, but next time I’ll buy powdered charcoal instead of having to powder it myself.

The recipe is as follows:

This is enough to make 2 bars:

white soap:
140g olive oil
88g coconut oil
32g NaOH (Lye)
60g H2O


Black soap:
100g coconut oil
19g NaOH
50g H2O + powdered charcoal to taste.