Solvent base, new formula compatible with almost all sealers and topcoats Pore-O-Pac™ Paste Grain Filler is a paste wood filler that is used for filling open grained woods. A fine blended mixture of silica, pigments, and a suitable vehicle, it provides a smooth, glass-like surface for subsequent finishing coats. Pore-O-Pac™ should be used over a wash coat of sealer. The use of our Grain Filler Scraper/Leveler is advised for even filling. A 24-hour dry time is necessary before topcoating. A ratio of 4 parts filler to 1 part of reducer is recommended.