I think it all depends on the manufacturer of the candle. I personally make soy; but ive bought a TON of paraffin candles over the years. Certain paraffin companies DO smoke quite a bit, and some dont. Its also the same with soy. Ive had store-bought soy candles soot horribly, and some that are totally clean. For a comparison: I purchased a Yank**, and a Colonial at Home candle (both are paraffin) right after Christmas. The Yank** smoked terribly, and the Colonial didnt smoke at all. Ive also purchased a pure soy candle from the grocery store recently that had so much soot on the jar, you couldnt even see through the glass!! There is alot of controversary about soy vs. paraffin; and to me, it still all boils down as to what candle company has made it. Just because i make soy candles, doesnt mean i dont still purchase paraffin. There are a few high-end paraffin companies that i still purchase regularly, and dont have a soot problem. I dont claim my candles as being a "better" type of wax. I let the customer decide for themselves. I have a few die-hard Yank** and Gold Canyon customers that say they love my candles better because they are more highly scented, but sooting doesnt bother them, so they still supplement their candle stock with other brands. Sooting is just so common when you burn candles, most people dont realize how bad it can get.