From Zinsser Premixed shellac:
Woodworkers, contractors and floor finishers use sanding sealers to speed the progress and improve the appearance of their finishing projects. For many years professional woodworkers and cabinetmakers used refined (dewaxed) shellac to seal surfaces before applying finish coatings. Refined shellac has all of the excellent properties of ordinary shellac (easy to use, fast drying, etc.) but no wax, making it compatible with all clear finishes
SealCoat offers the timesaving versatility of refined shellac in a pre-mixed 2 lb. cut 100% wax-free formula. It?s the perfect sanding sealer because it penetrates the surface, dries quickly, gives a rich tone to wood surfaces and since it contains no waxes or stearates, SealCoat is guaranteed to be compatible with oil-base polyurethanes, acrylic finishes, lacquers, catalyzed finishes and varnishes.
SealCoat Universal Sanding Sealer
Seals all types of wood surfaces including oak, maple, chestnut, mahogany, walnut, birch, poplar, cherry, etc. Recommended for interior woodwork, including paneling, molding, trim, windows, doors, cabinets, furniture, and toys. SealCoat is great for wood floors ? most floor finishing jobs can be completed in just one day. It?s the perfect sealer for acrylic finishes because it brings out the natural beauty of wood but will not turn yellow with age