What you will need:
Soap dye
Melt and pour soap (At least 1 1/2 pounds)
Small loaf pan
Sharp knife
Glass or microwave-safe container
Wax or parchment paper
Essential oil or soap fragrance
Tape
Line your loaf pan with wax or parchment paper so the finished soap won’t stick to your pan when it is complete. Cut excess and tape the seams together.
Cut about 2 cups of small cubes of melt and pour soap and place them in a microwave-safe bowl or cup. Melt at 30-second intervals in microwave until melted, stirring between each session. Add your first dye to achieve whatever color you choose for the first layer.
Melt two more cups of soap cubes and add whichever soap color you want for your next layer. While waiting for soap to melt, cut a few thin slices of soap from your un-dyed soap block. Make lengthwise cuts so you end up with long white strips. Pour half of melted soap into pan. Wait 30 seconds, and then add as many of the white soap strips that will fit while still leaving some room between them. Pour in the other half of soap to completely cover white strips.
Melt another 2 cups of soap for the top layer. Add your dye and pour onto top of pan. Wait for soap to cool. Remove from pan and then peel from wax or parchment paper. Cut into 1-inch thick bars.