Why is there a wasted half inch of cream or perfume in the bottom of a pump bottle?

The dip tube needs some clearance space from the bottom of the bottle to draw the product into it, says Ray Garofano — just as if you were drinking from a straw. As a result, some product is inevitably left behind. Before you feel cheated, though, know that many cosmetics companies overfill bottles to compensate. So if you buy a 1.7-ounce bottle of fragrance, say, chances are it contains close to 1.9 ounces, to make up for the bit that’s out of reach.

How come we can’t use every millimeter of lipstick or solid deodorant that’s in the tube?

A certain amount of product is required as a foundation to hold the product in its cup. Otherwise, it could jiggle or wobble and fall off its base. “There’s no easy way around that,” says Garofano. The cost of developing a mechanism to fix the problem would be far more than the value of all those wasted bits, he says. And that cost would ultimately be passed on to consumers.

Why is my anti-aging product pumping just air?

Many companies use airtight, one-way valves (small bottles with pump tops you can’t unscrew) to protect products from damaging exposure to oxygen. If the packages are not filled correctly and a small amount of air gets in, the pump won’t perform. The solution: Turn the product over and tap it on a hard surface two or three times to dislodge the air bubble, says Kevin Marshall.