CND Shellac Gel Base Coat. Size .42 oz/ 12.5 ml. One thin layer of Shellac Gel Base Coat is all you need. It cures in just 10 seconds under LED/UV lamp and provides the crucial foundation for the Shellac system, anchoring Shellac Color Coat to the nail. Formaldehyde, Toluene and DBP (Phthalate) FREE.