― Tightlining the eyes is nothing new to the makeup world. But to those still unfamiliar with this jargon, it's simply a technique to make the base of your upper lashes look thicker and fuller. ∙ While some use black eyeshadow or tigthlining cake with a small angled brush, I prefer waterproof black eyeliner. I find that it's easier to manipulate and is readily available. So for this tutorial, bring out your eyeliner and any makeup brush with a slim handle. ∙ (1) Barenaked eyes(2) [...].