I like my mascara brushes big and beefy—the more resistance I encounter when pulling the wand out of the barrel, the better. Or so I thought. Clinique just rolled out Bottom Lash Mascara, a sample-size tube of silky “thermal active” product with a micro-mini brush…we’re talking teeny. It’s designed, of course, to tackle that delicate lower lash line, but what really appealed to me was its ability to isolate those renegade lashes in the far-reaching corners of the upper lash line. I’m typically all about volume, but if it’s definition you’re after, look no further. You’ll find lashes you never knew you had. And the formula is equally impressive: a stretchable ingredient called bentonite gives lashes flexibility, while acrylates copolymer make the mascara impervious to cold water, sweat and humidity. I’ve actually never been a bottom lash girl—the top gets all the love—but I had a total "Twiggy moment" with this stuff, and it really did last all day without flaking or smudging. Whatever you’ll use it for, the point is: use it…don’t lose it. I did already, once. It’s easy to miss.