First things first: What is a tubing mascara? Well, as its name suggests, tubing mascaras create teeny polymer “tubes” around each individual lash to encourage separation and prevent smudging. “It is a (usually) silicone-based formula that coats every single eyelash, creating a lengthening effect,” adds celebrity makeup artist Tomy Rivero. “Because every single lash gets encapsulated into the tubes, lashes appear thicker, fuller, darker, and longer.”