TRADE VALUE PACK ZERO GLUE. ZERO MAGNETS. ZERO DRY TIME. So, how does it work? Silk Strong Hold Lash Bond Liner uses Bidirectional Film Forming Technology to create the ultimate hold for false lashes. This film-forming agent is known as a PSA (pressure sensitive adhesive). Pressure Sensitive Adhesives are a type of non-reactive adhesive which form a bond when light pressure is applied with a surface. PSA’s also display elastic properties which enable re-sticking! This functionality allows you to re-apply or adjust your lash if you first apply it incorrectly. This revolutionary and remarkable film-forming capacity toward both surfaces ensures a unique and reliable bond between the liner and lashes.