CND Toughen Up Strengthening Base Coat is a strengthening base coat that strengthens thin, weak nails and improves wearability. What it does: This base coat is dedicated to promoting healthy, long, and strong nails. Strong nail are less likely to break off or chip. What else you need to know: There is a CND Base Coat for everyone! Check out CND?s Stickey, Ridge Filling, and Shellac UV Gel Base Coats too!