Porcelain Prep & Primer is to be applied on clean natural lashes, which removes any residual oil and protein deposits from the lashes to improve glue attachment and extend the retention. Not only will it offer the best prep for extensions, it also contains tri-peptides that will nourish, condition, and strengthen the lashes! Recommended to use after Porcelain Shanpoo for full and fill sets. Dry primer completely before lash application.