All exterior woods grey into a patina colour over time, however UV-Protection Oil Tints have been developed to maintain the wood's natural colour with the use of pigments to optimally match the wood's natural characteristics. Ideal for windows, doors, cladding, fencing and other vertically structured joinery (not recommended for flat surfaces such as decking). Natural oil-based and microporous finish does not crack, flake, peel or blister. Water and dirt resistant, moisture regulating and reduces wood swelling and shrinkage. Osmo 425 Oak UV Protection Oil gives optimal protection from the sun, similar to Osmo 420 but it improves the UV resistance further by also having a small amount of Oak pigment. The oak pigment will darken the wood slightly and accentuate the wood grain but we recommend ALWAYS do a test before application, sample sachet available. For exterior use only. Especially recommended for vertical surfaces such as timber cladding, windows and doors Prolongs the renovation time significantly when used as a top coat for staining wood Contains active ingredients for the preventative protection against algae and fungal decay. Also available in 0.75 and samples sachets. 1 litre covers approx 16 square metres with 1 coat. Number of coats: 2 coats on raw wood, 1 coat for surface renewal - no sanding necessary.