Cat-Eye 9-D The Cat-Eye effect gel has been a hit in German studios for a few months. The most wonderful designs can be created on the nail with magnets. A fast and efficient nail art that can increase sales for every studio. Instructions: Apply the Cat-Eye 9-D gel to the fully modeled nail. Before the gel hardens, hold the magnets so that the colored metal pigments are brought to the surface. With a little practice, a wide variety of shapes can be created.