Decorative coatings and antitarnishing
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Due to the high conformality, uniformity, compactness, crack- and defect-free quality and typically bright, metallic luster of the ALD films they offer an attractive alternative to conventional decorative coating materials. Because of the abovementioned qualities, ALD method also saves material costs because only a nanometer-scale film can be enough to give the coated product the desired appearance, i.e. color, luster, reflectivity etc. This way, ALD brings added value to products: cheaper and more common materials can be given the appearance and properties of more expensive material by simply coating an ultra-thin film of this more expensive material on them, or, for example plastic base material can be given the appearance of metal with ALD-coating. ALD also ensures even and conformal coating even on surfaces and shapes that might be difficult to coat with other methods. The decorative film may also have a technical function, for example to protect the coated surface against corrosion or tarnishing or work as a moisture/oxygen barrier layer. ALD antitarnishing of coins and jewelry with Al2O3 and TiO2 thin film mixtures is, indeed, already in use in various related industries. Because of the ultra-thinness of the ALD antitarnish film, it also preserves the coated object's original appearance and enhances e.g. the natural shine of silver.