Old Masters Gel Stain is a highly pigmented, oil-based stain designed to achieve intense colors on interior surfaces. Gel Stain is designed for application on wood, plastic, fiberglass and other composition surfaces. Its thick formula allows for easy application and superior color control, necessary to achieve a rich and uniform color on most surfaces in a single application. Ideal for difficult to stain woods such as pine, poplar, maple, plywood and veneers, as well as non-porous surfaces including primed metal, composition, interior and exterior fiberglass doors and plastic moldings. Gel Stain comes in 23 factory mixed colors and can also be intermixed to achieve custom colors. For the exterior side of front entry doors (wood or fiberglass) please use an exterior clear finish to topcoat.