Interlux Flattening Agent. Designed to be used with Toplac, Brightside, Yacht Enamel and Interlux 1-part varnishes to produce a semi-gloss or matte finish. A clear solution specially formulated for mixing with Interlux 1-Part Finishes (Brightside Polyurethane and Yacht Enamels) and varnishes (Schooner Gold, Schooner, and Original) to produce a variety of gloss, satin or matte effects. For interior or exterior use.