The formulation of scratch-resistant coatings is a major goal for formulators. Thousands of scratch-resistant coatings already exist in our daily lives. Examples include automotive coatings, wood coatings, nail polishes, protective coatings for mobile phone displays, eyeglasses, etc. The traditional approach of incorporating inorganic particles has drawbacks such as gloss reduction, loss of transparency, reduced flexibility and changes in the rheology of the coating, generally causing poor flow and leveling. Additives containing alumina or silica nanoparticle concentrates in reactive diluents, water and solvent carriers have been developed for solvent-based and radiation-curable coatings to increase scratch resistance and abrasion resistance. This novel approach demonstrates improved scratch resistance with no increase in haze, no loss of gloss or detriment to other physical properties.