Swirl pillar candles are pillars that have two or more colors. The colors appear to be “swirled” together, hence their name! You’ll need to melt your candle wax in separate double boilers (or whatever you use to melt your candle wax). Measure enough wax to fill the pillar mold, and then place half in one melting pot and half in the other. Melt only one section at a time to the desired temperature, and then mix in the dye. Then and add your fragrance, if you’re using a fragrance, just before it’s time to pour the wax into the mold. Pour in your first color of wax and allow it just enough time to get a thick skin across the top, but not enough time to completely harden. As the first half of your candle is starting to set up, begin melting your second half of candle wax. Add your dye and fragrance, and slowly pour over the first color in your candle mold. If you want the colors to have the swirling effect, use a knitting needle or similar object and carefully pull it through in a circular motion to distribute the colors throughout the candle to create the swirl look. Found this on the web