Features: Wonder Is A Unique Clay Based Restoring System For Acoustic Ceiling Tiles. Permanently Bonds To The Surface Being Restored Without Compromising Acoustical Sound Absorption Or Fire Retardant Value. Covers Water Stains, Smoke And Fire Damage, Graffiti, Paint, Ballpoint Ink, Permanent Marker And Rusting Nail Heads, Avoiding The Need For Costly Replacement. Leaves A Clean, White Coating That Adds Years To Tile Life. Also Works As A Nonbleeding Primer/Sealer For Sign Painters, A Nongrain-Raising Primer For New Wood, A Base Coat For Wallpaper Or Vinyl Wall Coverings And As A Base Coat For Galvanized Metal.