Cut the soap base into 1-inch chunks.

Put 8 cubes of the soap base into a measuring cup and heat in the microwave for 30 seconds. Remove and stir very well for about 30 seconds. If the soap base is not quite melted yet, heat for an additional 30 seconds, then remove and stir until melted.

Add the red mica powder and stir until the color is solid. Add a few drops of fragrance if using.

Pour into 2 of the heart soap molds, filling 20 of the heart cavities.

Allow soap to sit undisturbed for about 1 hour.

Once set, unmold all 20 heart soap bars.

Divide the rest of the soap base into 3 measuring cups or dishes and heat according to step 2.

Once completely melted, stir one of the remaining colors into each of the melted soap bases, and stir well until a solid color has formed. Leave to cool slightly, as you do not want to pour hot soap.

Pour a small amount of one color into the 4” square soap mold, just enough to coat the bottom a bit.

Arrange a few red hearts in the mold, either standing up and/or on their side to ensure that you see a complete heart shape when you cut the soap. Spray with rubbing alcohol to help the layers stick.

Pour a small amount of another color in, allow to set slightly, then add a small amount of the third color, and allow to set slightly. Spray with rubbing alcohol to help the layers stick.

If needed, reheat the soap bases for 10-20 seconds, and stir well. Leave to cool slightly again, as you do not want to pour hot soap.

Proceed with a second layer of adding red hearts standing up and/or on their side. Then alternate pouring small amounts of each color into the mold. Spray rubbing alcohol between each layer to help the layers stick.

Proceed with a third layer of adding red hearts standing up and/or on their side. Then alternate pouring small amounts of each color into the mold. Spray rubbing alcohol between each layer to help the layers stick.

Proceed with a fourth layer of adding red hearts standing up and/or on their side. If the hearts are above the rim of the mold, that is ok, as it will be a cool design when you cut the soap into bars. Then alternate pouring small amounts of each color into the mold, until full. Spray rubbing alcohol between each layer to help the layers stick.

Allow the soap to set for 12-24 hours, then remove from the mold.

Use a soap cutter or large knife to cut the soap into 1-inch bars.

Use in your own bathroom, or package up to give as a gift!