First things first: what is tubing mascara? Well, as its name suggests, tubing mascaras form tiny polymer “tubes” around individual lashes to encourage separation and prevent clumping. “It’s (usually) a silicone-based formula that covers each individual lash, creating the effect of lengthening,” says the celebrity makeup artist. tommy rivero“Because each individual eyelash is encapsulated in tubes, the eyelashes appear thicker, denser, darker and longer.”