Whilst building this sort of candle, it is significant to make certain that it is completed as securely as possible. Making a botanical candle is generally a 4-step process. The first step is to make the "core" or a pillar, generally one which is 3" x 3-1/2". This candle can be made using a 131 F melt wax with some stearic or white coloring. The reason is that you want this candle to be white to offer a contrast to the outer shell. It is also important to size the wick to only burn this candle about 2-1/2" inches across. When this candle is finished, remove it from the mold leaving extra wick on the candle so that is may be threaded through the wick hole on the 4" x 4-1/2" mold. Thus far, the process used to make this candle is no different than as if you were making a standard pillar.
The second step is to take the completed 3" candle and center this candle into a 4" diameter candle mold. Once this is centered, you then insert the desired objects between the candle and the mold. (Getting the embeds in the exact area you desire will take some practice.) Once you have all the embed objects inserted and positioned in the manner you would like, you can then begin the third step. The third step is to take a higher melt point wax--we would recommend either the 4045 (141 F) or 5055 (152 F) wax--and pour between the candle and the mold. The 4045 and 5055 waxes are recommended for this application due to their translucent nature. One important note is that wax in its "natural state" is as translucent as you can get. Most additives are designed to give the wax an opaque finish. The fourth and final step is to remove the candle and level the bottom much the same way as a standard pillar.