So what are coffin nails? Ever since people started manicuring their nails, there have been two main shapes: round and square. Finally, we’re ready for different nail designs. Be happy, nail loverly, because we finally have something new. Coffin nails, sometimes referred to as ballerina’s nails are a new trend in nail art. They bend almost to the top, where they are square, to create visual interest and edges. If you’re tired of regular round nails and formal square nails, coffin nails are a great choice between the two and are the year’s best trends.