Grout & Tile Marker - Water based permanent paint. Change your grout color. Covers all grout stains. Fast Drying formula. Permanent on most surfaces. Water Resistant. Odorless. Non-Toxic. Available in 3 different colors. Grout-Aide™ Marker Pen renews grout instantly! Applicator is pinpoint accurate. Covers 100 - 150 linear feet. Marker is easy to use, dries rapidly and leaves clean, uniform grout lines (thick or thin) without harsh chemicals. Just shake & apply.