surface coating. Lacquer is a solvent-based paint or varnish that produces an especially hard, durable finish. Usually it is a rapidly drying formulation. Enamel paint is formulated to give an especially hard, usually glossy, finish. Some enamel paints contain fine glass powder or metal flake instead of the color pigments in standard oil-based paints. Enamel paint sometimes is mixed with varnish or urethane to improve its shine and hardness. A glaze is an additive used with paint to slow drying time and increase translucency, as in faux painting and for some artistic effects. A roof coating is a fluid that sets as an elastic membrane that can stretch without harm. It provides UV protection to polyurethane foam and is widely used in roof restoration. Fingerpaints are formulations suitable for application with the fingers; they are popular for use by children in primary school activities. Inks are similar to paints, except that they are typically made using finely ground pigments or dyes, and are not designed to leave a thick film of binder. They are used largely for writing, printing, or calligraphy. Anti-graffiti coatings are used to defeat the marking of surfaces by graffiti artists or vandals. There are two categories of anti-graffiti coatings: sacrificial and non-bonding: Sacrificial coatings are clear coatings that allow the removal of graffiti, usually by washing the surface with high-pressure water that removes the graffiti together with the coating (hence the term "sacrificial"). After removal of the graffiti, the sacrificial coating must be re-applied for continued protection. Such sacrificial protective coatings are most commonly used on natural-looking masonry surfaces, such as statuary and marble walls, and on rougher surfaces that are difficult to clean. Non-bonding coatings are clear, high-performance coatings, usually catalyzed polyurethanes, that do not bond strongly to paints used for graffiti. Graffiti on such a surface can be removed with a solvent wash, without damaging either the underlying surface or the protective non-bonding coating. These coatings work best on smooth surfaces, and are especially useful on decorative surfaces such as mosaics or painted murals, which might be expected to suffer harm from high pressure sprays. Urine-repellent paint is a very hydrophobic (water-repellent) paint. It has been used by cities and other property owners to deter men from urinating against walls, as the urine splashes back on their shoes, instead of dripping down the wall. Anti-climb paint is a non-drying paint that appears normal but