Wood sealers, such as Semco, Owatrol Deks Olje, and TotalBoat Danish Teak Sealer, are great at protecting and sealing wood to enhance the natural wood grain appearance, without leaving a film on the wood. You will find that teak sealers are generally linseed oil based, with UV resistance, mildewcides, and sometimes a colorant. For best results, these products recommend cleaning with a teak cleaner, and sanding the wood until smooth.