Behlen's water based grain fillers are easy to apply, and dry considerably faster than do oil-based types. The quick dry feature allows for application and final sanding in a single day, versus the need for at least 24 hours (and preferably 48 or more) with oil based fillers. Grain fillers are needed for a really smooth finish in open-pored woods such as red oak, walnut and mahogany. Wipe down must be faster, but otherwise application is very similar to oil-based fillers. No VOCs is another great feature.