Sealers need a carrier to evenly spread and take the active ingredients onto or into the surface. This carrier is either water and/or a non-water based solvent. There is no doubt that "water-based" sounds like a more desirable product but this term can be misleading. Many water-based impregnators still contain a considerable amount of solvent such as n-butyl acetate. As a general rule, non-water based sealers are more effective than water-based sealers. The main reasons they perform better include: they are able to wet and penetrate into the surface - this gives the sealer protection from weathering, cleaning, traffic, freeze-thaw, picture framing (critical on kitchen counter tops where water may by-pass any surface treatment) and efflorescence. Non-water based sealers can also be used over a previously impregnated surface and are suitable to treat resin treated stone, which is the norm for granite kitchen counters.