Real Seal "WT" wood treatment is a specifically formulated penetrating sealer and conditioner which reacts with properties inherent in all wood and wood-based materials. This product becomes an integral component of the material to which it is applied. Real Seal “WT” is not a surface coating. The treatment does not change the appearance of most wood species. “WT” seals the grain and makes wood more fire resistant. Sealing of the grain also makes the wood more impervious to insect infestation.