They may smoke more than metal core wick. Wick Pre Tabbed Votive Wick Additives Steric acid is a vegetable fat byproduct it is used to harden the wax and make it burn longer. It tends to cream out the colors use 3 tablespoons per pound. Vybar is used to disperse scent and color evenly through out the candle. The colors tend to cream out a little.
Mineral oil is used to get the mottling effect.
Use 3 tablespoons per 1lb of paraffin wax. Do not use vybar with mineral oil and do not water bath the candles. There are a lot of different types of molds on the market. For candles made at home for fun you can be creative and find common items for molds. Some of my favorite molds to use are yogurt cups, Dixie cups, frozen juice cans, and milk containers.