I think liquid dyes work best in 415 but humidity plays such a role in frosting, the more humid the area usually the more frosting you will get. It is just hard to avoid in 415. We would just let our customers know about the frosting and they didn't seem to mind, it is just harder when you are selling wholesale to a storefront then they may question why all the candles are frosted. I know alot of 100% soy candlemakers that use no dye as well.