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We all have a bevy of lip glosses floating around in our handbags, makeup totes and bathroom drawers. And it's no wonder, since one quick slick is all it takes for lips to go from ho-hum to a hot pout.

But have you ever wondered what makes lip gloss so shiny?

"The key to getting high shine is using materials with a high refractive index -- a technical measure of how light interacts with the material versus in air. Light is reflected from the surface as it reaches the material. The higher the refractive, index, the shinier the material," says Dr. Sarah Vickery, principal scientist with CoverGirl.

Yet making a high-shine lip gloss that's also comfortable to wear can be tricky.

"Materials with a refractive index greater than 1.4 are considered noticeably shiny by consumers. The major shine component in most lip glosses is polybutene. It's a polymer with a refractive index over 1.4, so it's extremely shiny, but it's also very sticky and tacky. This is why so many really shiny lip glosses have the unfortunate reputation of getting your hair stuck in them. The key to getting high shine without stickiness is to balance the polybutene with lightweight emollients," says Dr. Vickery.

Dr. Vickery's own strategic balancing of ingredients can be found in CoverGirl's ShineBlast Lipgloss, which cleverly toes the line between shine and comfort.

Who knew you could get a Ph.D in lip gloss mixology?