Varathane® 1 Quart Wood Conditioner (Case of 2) should be used on interior wood projects prior to finishing with an Oil-based stain to help prevent splotchy, uneven staining on soft and porous woods including birch, maple, alder, fir and pine. This proprietary soya Oil-based formula penetrates deeply sealing the wood and enabling it to achieve a deeper as well as richer tone. Works under any Oil-based stain.